After spending another sleepless night in chat here.. Iron82 helped me talk myself into a t56.. there are two main locations selling these kits..
http://www.fortesparts.com/tremec.cfm

and

http://www.keislerauto.com/gm/transmissions/corvette_68-82_6spd.asp

and to make this as complicated as possible.. there are three main gearing configurations

2.66, 1.78, 1.30, 1.0, 0.74, 0.5, 2.90R(which keisler calls 650hp version and forte calls viper/ls1 gearing)

2.66, 1.78, 1.30, 1.0, 0.80, 0.62, 2.90R (forte only)

2.97, 2.07, 1.43, 1.0, 0.80, 0.62, 3.28R (keisler calls it 475hp version , forte calls it aftermarket gearing)

im not sure i like the .50 6th gear as i think it would be a dog gear. im leaning towards the middle option of 2.66->0.62

im aiming for good launch gearing (around 10) and decent
cruising speed (70) in 6th at about 2000 rpm

my current m-21 launch gearing and cruise rpm are 7.4 & 3041 which is deficient on both ends

even have to change my diff gears too as staying at 3.36 will leave me with a launch of 8.9 and cruise of 1885

im thinking either 3.70 (L=9.8,CR=2076)
or 4.11 (L=10.9, CR=2306)

both kits will use the stock clutch assembly with new disc and use stock bell housing.

forte sells the transmission, clutch, new slip yoke, and speedo adapter for 2300$ and you have to modify your own trans mount crossmember.

keisler sell the transmission, clutch, pilot bearing, whole drive shaft and a kit to modify crossmemeber, and speedo adapter for 4K$

im not sure the extras you get with the keisler are worth it... but herein lies a problem

keisler says you have to modify the floor pan (cut a hole)

forte says you dont.

keisler offers an offest shifter to line up to muncie spec..

im waiting on an email from forte to see if they have the offset shifter.. (the price above assumes you will move your shifter back a little)

here is the gear calculator i used
http://www.5speedtransmission.com/gear_calculator.html

here is a howto on this conversion that doesnt mention cutting a hole..
http://temp.corvetteforum.net/c3/gwhite75/index.htm


I am always leery when it looks too easy..

I would go go for 2.66 for the launch and 4.11 for the diff gears.
Good Luck in your search.

IRON 82 |SIGhttp://www.C3VR.com/member_uploads/3601_3700/3624/iron82.jpg

Ben, there is another site. I'll meander through the forums as soon as I get time(Monday night?) and find it and post it. I think the prices were higher, but I can't remember for sure. If you decide to look I know it was September - December 2003 in the Driveline section.

Enjoy No Matter What!

Scot

sounds to me if it was my choice I would put 4.10 in and go for the one with .50 final gear. Jeeze I wish my 700r4 had these gears. My 3.08 sucks at launch and i want to go with a 3.55 or 3.70 once my budget permits. It does great on gas right now though! I dont know much about manuals or even t-56'es but you can have your cake and eat it too with that trans and gear ratio from what I gathered. my .02 cents awsome launch and good gas mileage on the highway.

|UPDATED|6/12/2004 9:53:11 PM (AZT)|/UPDATED|

Ok, so the massage chair lasted longer than expected...

http://www.c3vr.com/vrforums/message_go.asp?MID=23165

Not a T-56 but I'm not sure what it IS either..?

http://www.c3vr.com/vrforums/message_go.asp?MID=27392

Not sure if it helps much...

http://www.c3vr.com/vrforums/message_go.asp?MID=17495

I'm guessing you've already been to the link at the top but a few other URLs are there.

That's all I could find, and its my bedtime. Hope I've helped

Ciao!

Scot

found www.man-trans.com posted by aftershark

emailed them

lets see if they give me a third set of conflicting info

they dont do these conversions they sub them to keisler

|UPDATED|6/14/2004 2:30:51 PM (AZT)|/UPDATED|

Tumarr said: sounds to me if it was my choice I would put 4.10 in and go for the one with .50 final gear.

only issue with this (the .50 6th) is the 1860 rpm at 70 mph..

i think it will feel sluggish during further acceleration

it would be 1594 rpm at 60.. this would be a breaking the speed limit only gear.

this article talks about gearing for the t56 in practical terms
http://www.chevyhiperformance.com/techarticles/148_0405_trans/

I am trying to keep my cruising speed in my power band.

and keep my launch ratio between 9 and eleven..

remember a 4.11 with a .50 6th has a final drive ratio of 2.05 (like having a 2.05 rear end behind a 4spd) which will give great top end but no accelation. (i believe these were the gears in my c5 and 6th wasnt peppy enough for me)

whereas the 4.11 with .62 acts like a 2.55

the speed limit here in AR is 70.. so 80 is about as fast as I go..

do you guys think im smoking crack and 16-1800 rpms
is high enough for 60-70 mph ??

|UPDATED|6/13/2004 10:01:15 AM (AZT)|/UPDATED|

Well Its definitly a decision on your own preference. I figured the big block with a 270 magnum cam would have low enough grunt to cruise and pass well enough at 70 mph. My own vette feels fine on overdrive cruising along at 60 at around 1650 rpm. Thats my smallblock doing this. If I need to pass, it kicks down to 1.1 and zoooom... around the ford escort! my 3.08 shines out at these speeds though. I dont know about what kind of milage you are getting, but for me a low cruise rpm is why I put a overdrive trans in.

Added: You got 5th gear to throw at the slow escort. 2752 rpm: that should be in a good part of the 1800-5800 power band for the cam. I dont know if you feel like down shifting Though.

|UPDATED|6/12/2004 10:40:26 PM (AZT)|/UPDATED|

Tumarr said: Well Its definitly a decision on your own preference. I figured the big block with a 270 magnum cam would have low enough grunt to cruise and pass well enough at 70 mph. My own vette feels fine on overdrive cruising along at 60 at around 1650 rpm. Thats my smallblock doing this. If I need to pass, it kicks down to 1.1 and zoooom... around the ford escort! my 3.08 shines out at these speeds though. I dont know about what kind of milage you are getting, but for me a low cruise rpm is why I put a overdrive trans in.

downshifting is certainly an option.. i just dont want 6th to turn into a gutless wonder gear..

as for whether the BB will make up for it..

you may be right!!

thats one of the reasons im asking.. i really dont know how its going to feel and dont really want to spend money until im sure im making the right decision.. thanks for wieghing in.


got some more information... 5speedtransmission.com which is connected with forte parts has responded to my questions over the weekend (which is cool).. there is a physical difference between a viper/ls1 t56 and a GM aftermarket t56. they do not have an offset shifter for the aftermarket t56.

At this point im not even sure that keisler sells the offset shifter for the aftermarket, possibly just the ls1. they say they have two shifter locations for the aftermarket... im waiting on a response to find out if one of them is the muncie position.

so from what ive gathered so far..

I need the aftermarket transmission which does not require tunnel mods. this removes the 2.66->0.5 gearing option and is cheaper. the ls1/viper is much more expensive.

a gm aftermarket is a gm aftermarket is a gm aftermarket regardless of the internal ratios.


|UPDATED|6/13/2004 9:51:07 AM (AZT)|/UPDATED|

The idea a 6th gear from the factories was fuel mileage and lower emissions, not acelleration. Top end in the C5 is in 5th, not 6th. Just more food for thought.