Topic: Is this a bogus LT-1 engine?
in Forum: C3 Engines
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Lifetime Member[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]
Norsky 2007-03-29 21:40:03
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.
Jim Olson 
"The Toys"...!!! Save the Wave! 
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Palmyra, PA - USA
Joined: 2/9/2007
Posts: 26
Vette(s): 1970 Vette Convertible, driver
1981 Vette, driver
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?
If it was a true LT-1 the data plate would read 350 CID and 370 HP.
Jim Olson "The Toys"...!!! Save the Wave!
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Palmyra, PA - USA
Joined: 2/9/2007
Posts: 26
Vette(s): 1970 Vette Convertible, driver
1981 Vette, driver
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?
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Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
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.
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.
[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...!!! 
Jim Olson "The Toys"...!!! Save the Wave!
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!
[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
in Forum: C3 Engines
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