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Topic: Is this a bogus LT-1 engine?

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Is this a bogus LT-1 engine? (1/22)
3/21/07 8:32pm

Benelli 22
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Palmyra, PA - USA

Vette(s):
1970 Vette Convertible, driver 1981 Vette, driver

Joined: 2/9/2007
Posts: 26

My 1970 vette has a 1977 engine...not my choice for the engine but I got what I got. I knew the engine was NOM when I purchased the car. I have found a 1970 engine that the engine owner says is an LT-1 with 4,000 miles on the motor. I would like to make contact with someone who can give me advice on engine numbers and suffix and the economics of spending the extra money for the LT-1 engine. The suffix for this engine is XCD. This engine was never in a Corvette but was purchased over the counter from a GM dealer in 1970, again, as the owner says.

Thanks for you advice.

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Is this a bogus LT-1 engine? (2/22)
3/21/07 9:04pm

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SHELBYVILLE, TN - USA

Vette(s):
1976 L48 auto

1978 L82 4speed

1994 LT1 6speed

Joined: 7/5/2002
Posts: 3942

Well..... i cant find a "XCD" suffix... did find a "XC" which came up as a 1969 Camaro

XC

1969

350

255hp

4bolt

Powerglide

as for casting numbers... well... here's a link to a website with all that good stuff

http://www.chevy-camaro.com/chevy-camaro-engine-codes.asp

good luck hunting...

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Is this a bogus LT-1 engine? (3/22)
3/21/07 9:12pm

Gunslinger
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Frederick, MD - USA

Vette(s):
1969 convertible L71 427/435 4-speed black interior

Joined: 9/8/2003
Posts: 3398

I found two "XCD" suffixes...one is a 350 truck engine for 1999 rated at 255hp. The other is listed simply as a 350 crate engine...no further information.

Crate engines are built to varying levels of tune using the same block. No telling what that engine is without more information from it.

No way of proving it's an original LT-1 from 1970 unless someone can find information linking that suffix code to LT-1's. It could be built to LT-1 specs possibly.

Is this a bogus LT-1 engine? (4/22)
3/21/07 9:35pm

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North Charleston, SC - USA

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1975 L48 AT AC T-top

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According to the NCRS Pocket Spec Guide the Engine codes for 1970 LT1s were CTU and CTK. The CTK was new to 1970. Both were 350ci,370hp, 4 barrel Holly carb, mechanical lifters and T/I ignition.

Scott

Is this a bogus LT-1 engine? (5/22)
3/21/07 10:00pm

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Montesano, WA - USA

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had a really nice one. sold it to a good friend. Purchased 2004 custom coupe in Feb. 2009 did not tell anyone here until August 2009. BAD I KNOW.

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Posts: 1931

the other thing to remember is that thier was only about 1243 lt-1 install in all of the 70 vettes.

Is this a bogus LT-1 engine? (6/22)
3/22/07 5:20pm

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San Pedro, CA - USA

Vette(s):
1971, LT-1, T-top, 4-speed (M21), Mulsanne Blue, 3.70 rear, mostly original (sidepipes). 2006, Daytona Sunset Orange Coupe.

Joined: 5/26/2005
Posts: 239

The LT-1 engine was also used in the Z28 Camaros.

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Is this a bogus LT-1 engine? (7/22)
3/23/07 12:47pm

zgator
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Savannah, GA - USA

Vette(s):
1982CE,32,000 and counting. (fast!!) 1981 Vette, black on black. ZZ4 (quick!!)

Joined: 1/20/2005
Posts: 936

For the Z's I think it was CTC or CTK.One being auto the other a 4 speed.I shouid know this by heart,I've only had 5 of them!!! Those cars were so much fun.I'd be crusing around in second gear right about 3000rpm(The sweet spot)then jump on it and scare the carp out of the guy next to me.zgator2007-03-23 09:49:21

Is this a bogus LT-1 engine? (8/22)
3/23/07 1:53pm

1969 L46
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Jefferson City, MO - USA

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1969 L46 4 Speed Roadster

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One way to tell if it is from a Vette is to look at the partial VIN. It will have the "S" for St. Louis. If it from a Camaro it will have a "V" for Van Nuys or an "N" for Norwood. Look at the rear of the block to get the casting date. If it is a 4 bolt main 3970010 casting with a casting date between December of 1969 and August of 1970, it could be an LT1. The partial VIN would tell the tale if it hasn't been restamped.

Is this a bogus LT-1 engine? (9/22)
3/23/07 2:45pm

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Eagleville, PA - USA

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David,
I'm curious now how the above advice worked out for you. Let us know!

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Is this a bogus LT-1 engine? (10/22)
3/29/07 9:21pm

Benelli 22
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Palmyra, PA - USA

Vette(s):
1970 Vette Convertible, driver 1981 Vette, driver

Joined: 2/9/2007
Posts: 26

Hello to all who replied to my question...been out of town...sorry about the slow reply. Your collective responses are helpful. For now, I've decided to back off buying this engine. My restoration project has a way to go before I'm pressed for the engine. I'm certain that I'll have other restoration questions as this project goes forward.

One reply mentioned that there were a limited number of LT-1's. Can I tell from the VIN number if it is an original LT-1 car? In the area behind the gear shift lever is a data plate, but the data plate is well worn. From what I can determine, the data plate says 370 HP. It would be helpful if I had a build sheet, but I'm not certain where or it one is available. Any suggestions?

Is this a bogus LT-1 engine? (11/22)
3/30/07 12:32am

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Burke, VT - USA

Vette(s):
SOLD - "The Toy" - '70 Convertible
SOLD - "The Beast" - '90 ZR-1 (#682)
SOLD - "Betty" - '28 Ford Model A Tudor
Still have - "BLKBRRD" - '78 Pontiac Trans Am

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[QUOTE=ranger3]According to the NCRS Pocket Spec Guide the Engine codes for 1970 LT1s were CTU and CTK. The CTK was new to 1970. Both were 350ci,370hp, 4 barrel Holly carb, mechanical lifters and T/I ignition.

Scott
[/QUOTE]

There was also a CTV code for the 350/370 that was associated with the ZR1 performance package RPO. That's a pretty rare code though as only a couple of dozen or so are listed as a selected option.

From what I've been able to find the engine designation didn't appear in the VIN until 1972. The Engine ID Code/VIN located on the top right front side of the block would be the best clue as to what it is. So for an LT-1 engine it would be either VmmddCTU, VmmddCTK, or VmmddCTV (mmdd = the month and day the engine was assembled).

Another thing to check is the proper cylinder head casting number for an LT-1 should be either 3927186 (350/300, 350/350, and 350/370) or 3973414 (350/370 only). But heads are easily swapped so I wouldn't consider that an absolute confirmation. As was mentioned above it could be a crate engine build up to LT-1 specs.

btw - I dug this stuff out of the 'CORVETTE Restoration Guide 1968-1982' by Richard Prince and the '1953-82 Corvette Premiere Collectors Catalog' from YearOne (code RQ205). Hope it helped some.

IF the data plate on the console is the original one that would lend some credibility to the fact that the car was originally an LT-1. And as far as the build sheet is concerned, unless you find one somewhere on the car you're pretty much SOL on getting getting your hands on that info.

Norsky2007-03-29 21:40:03

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Is this a bogus LT-1 engine? (12/22)
3/31/07 1:14pm

Benelli 22
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Palmyra, PA - USA

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1970 Vette Convertible, driver 1981 Vette, driver

Joined: 2/9/2007
Posts: 26

Thanks Jim O.

The data plate on the console appears to original because it looks like it has 37 years of wear and tear. The data plate is 350 CID and 350 HP and 11:1 compression ratio. Does this help in identifing?

Is this a bogus LT-1 engine? (13/22)
4/2/07 1:15am

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Burke, VT - USA

Vette(s):
SOLD - "The Toy" - '70 Convertible
SOLD - "The Beast" - '90 ZR-1 (#682)
SOLD - "Betty" - '28 Ford Model A Tudor
Still have - "BLKBRRD" - '78 Pontiac Trans Am

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If it was a true LT-1 the data plate would read 350 CID and 370 HP.

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Is this a bogus LT-1 engine? (14/22)
4/3/07 9:41pm

Benelli 22
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Palmyra, PA - USA

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1970 Vette Convertible, driver 1981 Vette, driver

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Posts: 26

Gunslinger...you are amazing! Where did you locate the XCD suffix? A lot of others looked. The guy who is trying to sell me the engine told me that the engine was never actually in a Vette. The engine was built to LT- 1 specs and purchased over the counter from a GM dealer. The engine was put in a Jeep (go figure). Anyway, allegedly the engine has only 4000 miles. I know someone who is going to take a look at the engine for me.

Jim O. points out that the data plate should read 350 and 370. I know the data plate in my car is 350 and 350. Is there a downside to spending the money to put the LT-1 engine in a vette that was originally a 350 HP?

Is this a bogus LT-1 engine? (15/22)
4/3/07 10:13pm

Gunslinger
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Frederick, MD - USA

Vette(s):
1969 convertible L71 427/435 4-speed black interior

Joined: 9/8/2003
Posts: 3398

I have a book called "Chevy Small Block Suffix Codes...Factory Engine Identification Code Guide". I forget where I got it from but it is available. I think it was either Summit Racing or Jeg's, but I suffer from CRS...Can't Remember Sh!t.

If you want to put an LT-1 equivalent engine in your car...it's your car and your money. Do what you want. The only possible downside is maybe some loss of value from being a numbers matching vehicle (if it still is one anyway). That means something to some people (purists), and means nothing to other people.

As I said...it's your car. Do what makes you happy.

Is this a bogus LT-1 engine? (16/22)
4/3/07 11:08pm

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Burke, VT - USA

Vette(s):
SOLD - "The Toy" - '70 Convertible
SOLD - "The Beast" - '90 ZR-1 (#682)
SOLD - "Betty" - '28 Ford Model A Tudor
Still have - "BLKBRRD" - '78 Pontiac Trans Am

Joined: 1/23/2002
Posts: 7191

[QUOTE=Gunslinger] ... If you want to put an LT-1 equivalent engine in your car...it's your car and your money. Do what you want. ... [/QUOTE]

I agree. Seeing as the car's current engine isn't correct for it anyway replacing it with a spec built LT-1 would make the car a BLAST to drive. Then just get a new console plate to advertise the new engine's specs (and save the current one!) to make everyone else jealous...!!! LOL

LOL

LOL

LOL

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"The Toys"...!!! Save the Wave!

Where I've been in a Corvette...!!!

Is this a bogus LT-1 engine? (17/22)
4/4/07 8:05pm

daveb12
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KERNERSVILLE, NC - USA

Vette(s):
1968 L-71 convertible

Joined: 1/13/2004
Posts: 1355

You may want to compare the price of a brand new warrantied crate motor to the price of one you can't see inside of.

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Is this a bogus LT-1 engine? (18/22)
10/1/10 9:10am

knickick
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Kansas, KS - USA

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Handsome

Joined: 10/1/2010
Posts: 1

I know where to find them. If you are interested to know it, just PM me. :D

Is this a bogus LT-1 engine? (19/22)
10/1/10 11:25am

MikeMc71
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Tucson, AZ - USA

Vette(s):
1970 White L-46 Air Roadster, 1971 White LT1 Coupe, 1971 Red Auto Air Coupe, 383 stroker, 430 HP, 2002 Millennium Yellow Auto Coupe

Joined: 10/7/2007
Posts: 341

Here is a little info that might help. The LT-1s had different front springs fron the normal Vettes. The wire on them was actually a smaller diameter, don't ask me why, they just were. If it is a 350/350 car, it will not have the TI ignition, but it will still be 11:1 comp ratio. LT-1s ONLY came with HD rear ends at 3.70, a single fuel line from the tank, (the L-46 have two lines), they ONLY came with M-21 Muncies, and NEVER had A/C offered until 1972. As Norsky mentions, the ZR-1 package had all of the options as the LT-1, BUT it also had the HD brake package, HD sway bars, and a few other changes.

It sounds to me like you might have the L-46 car, which is a VERY nice car as well, HEY I own one!

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Is this a bogus LT-1 engine? (20/22)
11/3/10 1:57am

playtimeover
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Minneapolis, KS - USA

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Blue

Joined: 11/2/2010
Posts: 2

[QUOTE=Benelli 22]My 1970 vette has a 1977 engine...not my choice for the engine but I got what I got. I knew the engine was NOM when I purchased the car. I have found a 1970 engine that the engine owner says is an LT-1 with 4,000 miles on the motor. I would like to make contact with someone who can give me advice on engine numbers and suffix and the economics of spending the extra money for the LT-1 engine. The suffix for this engine is XCD. This engine was never in a Corvette but was purchased over the counter from a GM dealer in 1970, again, as the owner says.

Thanks for you advice.

[/QUOTE]

My friend knows about the 1977 engine. If you are interested, PM me and I will contact him so that he can help you. Will wait for your further response. :D

Is this a bogus LT-1 engine? (21/22)
11/20/10 9:26am

spf70
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Scarborough, ME - USA

Vette(s):
70 LT1 Roadster 72 T-top

Joined: 10/20/2010
Posts: 1

My first post on this forum! Looks like this thread is a little old but thought I would through in my 2 cents. First, congrats on owning a 70.

I have a 70LT1 Vert and have been looking for the right parts to build the motor back to original. It is worth it to me as I am sure the car is an 70 LT1. I have probably looked into around 25 engines claimed to be an LT1 and only one of them was real and that came out of a Z28.

One thing is certain; the numbers you have listed mean this is not an LT1 engine. If it were a factory replacement block for that year it would be a CE block.

Other things you want to look for to see if it was "built to a 70 LT1", cant tell you how many times I have heard that and most aren't even close -

Solid lifter cam (3972182), aluminum GM intake, Holly card list number 4555, crank will be a forged 1182 (3941182 is the full number but you should se the 1182), pistons will be domed number 3989051, fuel pump will have one line in only.

Before I invested money building an original LT1 I would make sure the car is an LT1. I only say that because you can build a better motor for less money as technology has changed a lot since 1970.

Real quick checks on the car that should tell you – single fuel line with no return lines, 6500 red line on the tach, should have either the transistor ignition or the three holes where it used to be on the front driver side fender well, no expansion tank on the brass/copper radiator, heavy duty U clamps holding the U joints on the half shafts. They can have several different rear ends – mine has a 4-11 so that won’t help you.

Long first post, sorry I ama little to close to this subject. Let me know if you want more info.

Steve

Is this a bogus LT-1 engine? (22/22)
11/20/10 9:15pm

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North Charleston, SC - USA

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1975 L48 AT AC T-top

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Steve,

Thanks for the very informative post. No apologies necessary for the length. We are all looking to build our knowledge base, regardless of how long we've been here or how many posts we have. Great to have you with us.

Scott

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