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8/21/12 2:58pm - Reply: 'Re: change differential ratio'
corvette440hp Lifetime Member
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Joined: 7/2/2006
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dapperdan said: How tough was it to do the removal and install of the rear end?

Dan that's a loaded question. It all depends on how mechanical you are. Also if you have the tools. You really need to get a sevice manual.................. On a different note: Im sure that you miss your cat......he or she was beautiful.

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8/21/12 3:54pm - Reply: 'Re: change differential ratio'
my7t1 Lifetime Member
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Dorr, MI - USA

Vette(s):
71 Colonnade Hardtop Coupe Torch Red with black interior originally L48 built to push around 360hp

Joined: 8/21/2002
Posts: 2580
Welcome Dan. My 71 L48 has 3:36 gears, 4spd trans. At 70 mph I'm right around 2900 R's. Now the good news besides the mileage I get, my punched out 383, mild cam, and some other toys thrown in I have absolutely no problems breaking em loose and roasting the back tires.
I agree with others that's my ratio of choice.


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11/15/12 10:47am - Reply: 'Re: change differential ratio'
tonytheroofer
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Rochester, NY - USA

Vette(s):
1980 L- 82 fully restored and upgraded.

Joined: 6/12/2012
Posts: 95
I would leave the rear alone , the gains in MPG will be little at best and the drive-ability around town will off set any highway gains in MPG you get . So leave the rear alone and swap the transmission because you then maintain all the power and driveablity BUT get positive and solid MPG gains you will notice at the pump.

I having an automatic just dropped in the 700R4 trans with a 3.55 rear it is wow .. You can hardly hear the motor on the expressway in OD. 

Is the trans swap more ? yes however driving experience alone should make you feel like the money was very well spent . 


|UPDATED|11/15/2012 7:47:04 AM (AZT)|/UPDATED|


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1980 , ZZ430 , 3.92 rear , 700R4 2400 stall NEW EZ EFI 
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11/15/12 4:01pm - Reply: 'Re: change differential ratio'
dapperdan
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COLUMBUS, NC - USA

Vette(s):
2011 Grand Sport Coupe, 6-speed 1977 Coupe L82, 4-speed

Joined: 8/19/2012
Posts: 42
My '77 coupe is rare.  It is one of 2060 out of about 50,000 that had the combination of an L82 engine and a 4-speed transmission.  I don't want to change the trans.

I had a '76 L82 with a 4-speed many years ago and it had the 3.36 differential.  It was not a screamer, like this '77 model.

The gas mileage is one thing, but the wear and tear on the engine is what concerns me.  My '77 only has 31,000 original miles on it but the engine has been revving way too high throughout those miles.  I want to calm it down some.

I have 2011 GS that I can drive for performance purposes, so I don't care about the '77 as a performance car.  i just like its looks and the way it handles.  It is not going to be driven hard by me.


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11/15/12 6:00pm - Reply: 'Re: change differential ratio'
tonytheroofer
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Rochester, NY - USA

Vette(s):
1980 L- 82 fully restored and upgraded.

Joined: 6/12/2012
Posts: 95
dapperdan said: My '77 coupe is rare.  It is one of 2060 out of about 50,000 that had the combination of an L82 engine and a 4-speed transmission.  I don't want to change the trans.

I had a '76 L82 with a 4-speed many years ago and it had the 3.36 differential.  It was not a screamer, like this '77 model.

The gas mileage is one thing, but the wear and tear on the engine is what concerns me.  My '77 only has 31,000 original miles on it but the engine has been revving way too high throughout those miles.  I want to calm it down some.

I have 2011 GS that I can drive for performance purposes, so I don't care about the '77 as a performance car.  i just like its looks and the way it handles.  It is not going to be driven hard by me.


Well glad you cleared that up after several ideas of it having been mentioned to you.

As far as gears at 60mph you are not hitting 3500rpm ,  unless you installed short tiny tires but that cant be because it is an original 77 right ? Or you have a 4.56 rear gear set other wise ...... At 60mph your car is going to turn 2723 rpm .. Using a 225/70/15 tire .. If it has an optional 255/60/15 it will turn 2758 at 60mph . .If you gear change it you will save 250 rpm with a 3.36 .Nothing to write home about and nothing you will recover expense wise making the change and nothing that will extend engine life. 

PS) you would have to run 75mph to hit 3400 .. if your tach is showing 3500 at 60mph you have an issue because you in no way shape or form could hit that rpm at 60 in a stock 1977 corvette at 60mph



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1980 , ZZ430 , 3.92 rear , 700R4 2400 stall NEW EZ EFI 
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11/16/12 12:02pm - Reply: 'Re: change differential ratio'
dapperdan
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COLUMBUS, NC - USA

Vette(s):
2011 Grand Sport Coupe, 6-speed 1977 Coupe L82, 4-speed

Joined: 8/19/2012
Posts: 42
I put a mark on the drive shaft and had my wife turn one of the rear wheels one turn.  The drive shaft turned 3 & 3/4 turns, approximately.  I agree with all of your numbers on the RPMs at different speeds.  I know the formula for computing the RPMs.  I have a new set of Radial T/As on the car:  225/R70/15.  The tire measures about 27 inches in diameter.  Thus, RPMs at 65 mph are calculated:  (65 X 336 X 3.70) / 27 = 2993.  Maybe, I indicated a higher RPM in a previous note, and maybe my Tach and/or speedometer are not quite right.  I was just trying to indicate that the 3.70 rear end is a really low gear ratio for this car.  

I realize that a 3.36 rear end would get me about a 10% reduction in RPMs at all speeds 336/370 = 0.908.  But that would help reduce the general feel and vibration level of the car at highway speeds.  The 350 V8 does not have to run that fast to accommodate the weight and drag of the car.  Chevy put the 3.70 in the performance car to give the owner the feel that the car was responsive, I think???The same car in 1976 had a 3.36 as the standard differential.  I don't think the '76 had an A.I.R. pump, so it had a little more rear wheel HP.

I got a quote from Keisler Engineering on a 5-speed manual transmission.  It's a little shy of $3,000, but the tranny has a very low 1st gear (3.37) and 2nd is 1.99.  So, it is not a close ratio setup.  They had a better combination, but don't produce it any more.  One of their engineers indicated that I wouldn't like the current combination. My current 1st gear is 2.64 and that is a really low starting ratio with the 3.70 rear end.  My car is easily driven at 20 mph in 4th gear.  The engine doesn't lug. 

Hey, I thought this was supposed to be a friendly site?!?  I just found out that my newly acquired car is a rare one.  Don't think the previous owner realized that.  He only drove the car 3000 miles in 24 years, so he probably wasn't concerned about drivability.  I was just seeking advice from others that may have had the same questions and some possible solutions. 


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11/16/12 2:27pm - Reply: 'Re: change differential ratio'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19449
Ok folks....before this gets any further, let's just all try to be helpful without being sarcastic, or anything like that. It's hard to tell the emotion behind printed(typed) words, and sometimes it looks like someone is talking trash, or talking down to someone. I hope that is not the case here. Most of our long time members do joke around, and talk a little smack to each other every once and a while, but it is all in fun. We want to keep it that way for everyone.Hug

Dan, you can get the diff ratio code from the bottom of the diff. That would at least tell ya what it was originally built with, assuming it has not been changed....a lot of them have been over the years. If it does indeed have a 3.70 in it now, then I think going to the 3.36 would be just about perfect for what you are looking for, RPM-wise. My 3.36 & 225/70R15s runs just shy of 3000 rpms @70mph.

http://s77.beta.photobucket.com/user/aapple2/media/brakes/Differential/codes.jpg.html?sort=3&o=1





|UPDATED|11/16/2012 11:27:35 AM (AZT)|/UPDATED|


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11/16/12 2:01pm - Reply: 'Re: change differential ratio'
myhigh76
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Traverse City, MI - USA

Vette(s):
1976 coupe 35K miles

Joined: 12/15/2011
Posts: 6
I have the same concern with my '76 (38 K miles) The engine feels like it labors so much in 4th. gear at 60-65 mph.  I also am interested in driving this car a distance without feeling I need to shift into another gear...I know very little 'bout gear ratios but would like to get more answers ...Not certain what gear I am running currently. Happy to see someone with the same dilemma.  Any suggestions are appreciated!!


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11/16/12 6:56pm - Reply: 'Re: change differential ratio'
tonytheroofer
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Rochester, NY - USA

Vette(s):
1980 L- 82 fully restored and upgraded.

Joined: 6/12/2012
Posts: 95
The gears of a std 4spd are 1.00 in 4th ,, same with all the automatics 1.00 in 3rd .. 

I have the 1980 with a 3.55 rear and at 70 or so i was at 3200 plus or minus a little and that also was not in my opinion a good place to run the engine day in and day out , so I would drive 55 and be the corvette every one passed ha ha ha ha ha ..................

The solution for me was the 700R4 including a new cross member and most importantly a new shifter detent that not only gave correct access to all 4 forward gears but also gave me the correct lens readings so when you look down at it you see  R N D 3 2 1. It looks so stock only us corvette nuts will notice and I bet ya people who see it will ask is this an 82 ?

Is it factory original ? NO , but the sad fact  is unless it is a 0 mile or 50 mile original its value today and for the foreseeable future is low . ( c-3 low 5k high maybe 15k ) Low mileage heated storage never touched museum piece 25k to 35k and that is not going to apply to a 77 or 80 .. 

With the 700R4 My first gear is now 3.06 when multiplied by rear ratio I am getting a 10.8 t/q multiplier that a good street car would want if it seeks decent performance, and I am  now 30% less rpm to go 70 add the lock up converter and I drop 100 or so more rpm when on the highway. Making the car a dream to drive and I have to be careful because I am so use to the revving noise I tend to keep my foot in it and realize I am at 90 lol... 

So it is all a compromise , even original numbers matching can be maintained by storing the th350 in a crate wrapped in plastic .. I long ago loving the body style decided power and good street manners trumped all else yet also felt the car should look correct to observers and even under my hood it should be less flash and more oem in how it looks. 

430hp
430tq
3.55 rear 

And to look at it and here it one would be hard pressed to suggest any serious changes have ever been made and I am proud of that . 


____________________________________
1980 , ZZ430 , 3.92 rear , 700R4 2400 stall NEW EZ EFI 
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11/17/12 11:22am - Reply: 'Re: change differential ratio'
dapperdan
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COLUMBUS, NC - USA

Vette(s):
2011 Grand Sport Coupe, 6-speed 1977 Coupe L82, 4-speed

Joined: 8/19/2012
Posts: 42
You can check the differential's gear ratio by marking the drive shaft and have someone turn a back wheel one complete turn, while you count the number of times that the drive shaft turns.  That is a very simple way of determining the gear ratio.  Most of the members on this site have recommended the 3.36 differential for those with a 3.70.

I have talked to several different suppliers and they won't make a clear recommendation, understandably.  However, one of these suppliers indicated that owners have even gone to the 3.08 to quiet down the RPMs.  That would make the car much better at highway speeds, but would affect the "hole shot."  

I am going to have a different differential put into my '77.  I will keep the site posted on what I decide upon, but it is most probably going to be the 3.36.  The speedometer gear has to be changed.  That is a simple change and the correct gear can be acquired from Ecklers or several other suppliers.


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11/17/12 2:37pm - Reply: 'Re: change differential ratio'
Case75
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, - Canada

Vette(s):
1975 Corvette 383 stroker w/Patriot 190 heads, Eagle stroker kit, Comp 279TH7 cam, DUI distributor, Edelbrock 7116 intake, Edelbrock 1806 carb, Hedman Hedders, TH400 w/TCI Breakaway 2400 stall, Transgo 1-2 shift kit.

Joined: 6/19/2012
Posts: 230
tonytheroofer said: The gears of a std 4spd are 1.00 in 4th ,, same with all the automatics 1.00 in 3rd .. 

I have the 1980 with a 3.55 rear and at 70 or so i was at 3200 plus or minus a little and that also was not in my opinion a good place to run the engine day in and day out , so I would drive 55 and be the corvette every one passed ha ha ha ha ha ..................

The solution for me was the 700R4 including a new cross member and most importantly a new shifter detent that not only gave correct access to all 4 forward gears but also gave me the correct lens readings so when you look down at it you see  R N D 3 2 1. It looks so stock only us corvette nuts will notice and I bet ya people who see it will ask is this an 82 ?

Is it factory original ? NO , but the sad fact  is unless it is a 0 mile or 50 mile original its value today and for the foreseeable future is low . ( c-3 low 5k high maybe 15k ) Low mileage heated storage never touched museum piece 25k to 35k and that is not going to apply to a 77 or 80 .. 

With the 700R4 My first gear is now 3.06 when multiplied by rear ratio I am getting a 10.8 t/q multiplier that a good street car would want if it seeks decent performance, and I am  now 30% less rpm to go 70 add the lock up converter and I drop 100 or so more rpm when on the highway. Making the car a dream to drive and I have to be careful because I am so use to the revving noise I tend to keep my foot in it and realize I am at 90 lol... 

So it is all a compromise , even original numbers matching can be maintained by storing the th350 in a crate wrapped in plastic .. I long ago loving the body style decided power and good street manners trumped all else yet also felt the car should look correct to observers and even under my hood it should be less flash and more oem in how it looks. 

430hp
430tq
3.55 rear 

And to look at it and here it one would be hard pressed to suggest any serious changes have ever been made and I am proud of that . 

More and more I am beginning to think this is the best option fo me. My L48 has the original THM400; I have looked at a Keisler RS500 kit as I wish my car had a manual. It can be converted with their kit very well but it gets expensive. I've been looking at a Bowtie Overdrive conversion with the 700R4, the crossmember, TV cable and shifter and the price is more reasonable with nearly similar performance/mileage gains. I have the 3.08 rear; my THM400 has a 2.48 first vs the 700R4 with the 3.06 first. This will give me the equivalent hole shot of a 3.80 rear gear with the .70 overdrive netting a 2.16 highway ratio. Best of both worlds I think. I agree that my '75 will only increase in value about equal to inflation, maybe a bit better. I bought the car for me to enjoy and getting lousy gas mileage is keeping some of the enjoyment out of it.

|UPDATED|11/17/2012 11:37:41 AM (AZT)|/UPDATED|


____________________________________
 
Build Date: May 7, 1975. 383 w/267 RWHP/310 RWTQ
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11/18/12 1:00pm - Reply: 'Re: change differential ratio'
ROCKRDR
Former Member
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Lakeside, AZ - USA

Vette(s):
1975 C3 Stingray

Joined: 7/23/2012
Posts: 126
Case75 said:
tonytheroofer said: The gears of a std 4spd are 1.00 in 4th ,, same with all the automatics 1.00 in 3rd .. 

I have the 1980 with a 3.55 rear and at 70 or so i was at 3200 plus or minus a little and that also was not in my opinion a good place to run the engine day in and day out , so I would drive 55 and be the corvette every one passed ha ha ha ha ha ..................

The solution for me was the 700R4 including a new cross member and most importantly a new shifter detent that not only gave correct access to all 4 forward gears but also gave me the correct lens readings so when you look down at it you see  R N D 3 2 1. It looks so stock only us corvette nuts will notice and I bet ya people who see it will ask is this an 82 ?

Is it factory original ? NO , but the sad fact  is unless it is a 0 mile or 50 mile original its value today and for the foreseeable future is low . ( c-3 low 5k high maybe 15k ) Low mileage heated storage never touched museum piece 25k to 35k and that is not going to apply to a 77 or 80 .. 

With the 700R4 My first gear is now 3.06 when multiplied by rear ratio I am getting a 10.8 t/q multiplier that a good street car would want if it seeks decent performance, and I am  now 30% less rpm to go 70 add the lock up converter and I drop 100 or so more rpm when on the highway. Making the car a dream to drive and I have to be careful because I am so use to the revving noise I tend to keep my foot in it and realize I am at 90 lol... 

So it is all a compromise , even original numbers matching can be maintained by storing the th350 in a crate wrapped in plastic .. I long ago loving the body style decided power and good street manners trumped all else yet also felt the car should look correct to observers and even under my hood it should be less flash and more oem in how it looks. 

430hp
430tq
3.55 rear 

And to look at it and here it one would be hard pressed to suggest any serious changes have ever been made and I am proud of that . 

More and more I am beginning to think this is the best option fo me. My L48 has the original THM400; I have looked at a Keisler RS500 kit as I wish my car had a manual. It can be converted with their kit very well but it gets expensive. I've been looking at a Bowtie Overdrive conversion with the 700R4, the crossmember, TV cable and shifter and the price is more reasonable with nearly similar performance/mileage gains. I have the 3.08 rear; my THM400 has a 2.48 first vs the 700R4 with the 3.06 first. This will give me the equivalent hole shot of a 3.80 rear gear with the .70 overdrive netting a 2.16 highway ratio. Best of both worlds I think. I agree that my '75 will only increase in value about equal to inflation, maybe a bit better. I bought the car for me to enjoy and getting lousy gas mileage is keeping some of the enjoyment out of it.



I still need to see what my rear ratio is as well, I'm thinking the 700R4 conversion as well
has anyone done this yet...on a budget :) the trannys are pretty cheap on ebay. someone 
has one out here for 300.00 but I dont know what im looking for in a tranny.
I  guess this might be subject for a diff topic.



____________________________________
1975 Corvette Coupe 
My first Vette.....trying to fix stuff

My Project:
https://docs.google.com/folder/d/0B6uOAIjGf3cWejQ5TjNkcVRybGs/edit
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11/18/12 2:41pm - Reply: 'Re: change differential ratio'
Case75
Former Member
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, - Canada

Vette(s):
1975 Corvette 383 stroker w/Patriot 190 heads, Eagle stroker kit, Comp 279TH7 cam, DUI distributor, Edelbrock 7116 intake, Edelbrock 1806 carb, Hedman Hedders, TH400 w/TCI Breakaway 2400 stall, Transgo 1-2 shift kit.

Joined: 6/19/2012
Posts: 230
ROCKRDR said:
Case75 said:
tonytheroofer said: The gears of a std 4spd are 1.00 in 4th ,, same with all the automatics 1.00 in 3rd .. 

I have the 1980 with a 3.55 rear and at 70 or so i was at 3200 plus or minus a little and that also was not in my opinion a good place to run the engine day in and day out , so I would drive 55 and be the corvette every one passed ha ha ha ha ha ..................

The solution for me was the 700R4 including a new cross member and most importantly a new shifter detent that not only gave correct access to all 4 forward gears but also gave me the correct lens readings so when you look down at it you see  R N D 3 2 1. It looks so stock only us corvette nuts will notice and I bet ya people who see it will ask is this an 82 ?

Is it factory original ? NO , but the sad fact  is unless it is a 0 mile or 50 mile original its value today and for the foreseeable future is low . ( c-3 low 5k high maybe 15k ) Low mileage heated storage never touched museum piece 25k to 35k and that is not going to apply to a 77 or 80 .. 

With the 700R4 My first gear is now 3.06 when multiplied by rear ratio I am getting a 10.8 t/q multiplier that a good street car would want if it seeks decent performance, and I am  now 30% less rpm to go 70 add the lock up converter and I drop 100 or so more rpm when on the highway. Making the car a dream to drive and I have to be careful because I am so use to the revving noise I tend to keep my foot in it and realize I am at 90 lol... 

So it is all a compromise , even original numbers matching can be maintained by storing the th350 in a crate wrapped in plastic .. I long ago loving the body style decided power and good street manners trumped all else yet also felt the car should look correct to observers and even under my hood it should be less flash and more oem in how it looks. 

430hp
430tq
3.55 rear 

And to look at it and here it one would be hard pressed to suggest any serious changes have ever been made and I am proud of that . 

More and more I am beginning to think this is the best option fo me. My L48 has the original THM400; I have looked at a Keisler RS500 kit as I wish my car had a manual. It can be converted with their kit very well but it gets expensive. I've been looking at a Bowtie Overdrive conversion with the 700R4, the crossmember, TV cable and shifter and the price is more reasonable with nearly similar performance/mileage gains. I have the 3.08 rear; my THM400 has a 2.48 first vs the 700R4 with the 3.06 first. This will give me the equivalent hole shot of a 3.80 rear gear with the .70 overdrive netting a 2.16 highway ratio. Best of both worlds I think. I agree that my '75 will only increase in value about equal to inflation, maybe a bit better. I bought the car for me to enjoy and getting lousy gas mileage is keeping some of the enjoyment out of it.



I still need to see what my rear ratio is as well, I'm thinking the 700R4 conversion as well
has anyone done this yet...on a budget :) the trannys are pretty cheap on ebay. someone 
has one out here for 300.00 but I dont know what im looking for in a tranny.
I  guess this might be subject for a diff topic.


In 1975, L48 automatics came with the 3.08 rear and a 2.73 rear was optional (why anyone would order this I can't imagine!). If it was an L48 manual, it came with the 3.36 gears and the 3.08 was optional. L82 autos came with 3.36 gears with 3.55 being optional. L82 4 speed wide ratios came only with 3.55 gears while close ratios had 3.55 std and 3.70 optional. :)

____________________________________
 
Build Date: May 7, 1975. 383 w/267 RWHP/310 RWTQ
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11/18/12 5:51pm - Reply: 'Re: change differential ratio'
dapperdan
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COLUMBUS, NC - USA

Vette(s):
2011 Grand Sport Coupe, 6-speed 1977 Coupe L82, 4-speed

Joined: 8/19/2012
Posts: 42
Thank you for the data on the various combinations of the '75 Corvette differentials.  Those just re-enforce my wanting to change my '77 L82 from a 3.70 to a 3.36.

I wonder how the L48 did with the 3.08 with a 4-speed???  I think that would have been a good combination for mpg, but not too good for performance.  Anybody out there have/had that combination?


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11/19/12 12:16am - Reply: 'Re: change differential ratio'
ROCKRDR
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Lakeside, AZ - USA

Vette(s):
1975 C3 Stingray

Joined: 7/23/2012
Posts: 126
ok checked mine, numbers are AWW 318 E2 so I guess I have the 3.08 in mine

____________________________________
1975 Corvette Coupe 
My first Vette.....trying to fix stuff

My Project:
https://docs.google.com/folder/d/0B6uOAIjGf3cWejQ5TjNkcVRybGs/edit
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11/19/12 12:49am - Reply: 'Re: change differential ratio'
dapperdan
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COLUMBUS, NC - USA

Vette(s):
2011 Grand Sport Coupe, 6-speed 1977 Coupe L82, 4-speed

Joined: 8/19/2012
Posts: 42
How well does your car perform?  What kind of MPG do you get???

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11/20/12 1:01pm - Reply: 'Re: change differential ratio'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19449
I'm loosing it...
somewhere in this thread(or the one on 700s), someone mentioned having the original gear set out of their car from the PO, and I mentioned how to determine the ratio of that gearset by counting the teeth, or looking at the markings. Anyway, I cannot find that post now, so I'll add the pic I was looking for at the time here instead, so ya'll will know what to look for.....



Not ALL gearsets will have the actual ratio stamped on them, as this one does....but they will all have the ring and pinion tooth counts stamped(or engraved). Thumbs Up


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Joel Adams
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11/21/12 10:15am - Reply: 'Re: change differential ratio'
Jaws79 Lifetime Member
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Sykesville, MD - USA

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1979 Corvette Coupe Corvette Light Blue Midnight Blue interior Mirrored Glass T-tops

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Man, better use that ratio for racing only!
 
Barry
 
Shocked


|UPDATED|11/21/2012 7:15:32 AM (AZT)|/UPDATED|


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11/21/12 1:45pm - Reply: 'Re: change differential ratio'
Adams' Apple Lifetime Member
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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

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Or pullin stumps....or rock climbin...or just 'cause it's there....and it was free...LOL

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Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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3/18/13 7:46pm - Reply: 'Re: change differential ratio'
F4Gary Gold Member
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Grapevine, TX - USA

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3.36 would be perfect.  I wish I had done that.

So can I put a 2.64 first gear in my tranny if it doesn't already have one?  I assume the LT-1 came with a close ratio tranny.

As far as originality in your rear end.  Wink  I don't think the NCRS checks the actual rear end ratio.  I assume they just check the numbers stamped on the rear end housing.  Kinda like changing the internals of an original engine.  What they can't see they can't check.

Go for it.


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