Engine ID Help

[Jeffro]

I'm looking another 1970 vette to purchase. The owner thinks the engine is original but the engine identification number doesn't match anything I have seen.

The ID on the engine pad is KTC51GOV

Any ideas on the origin of the engine block?

 

[Paul Borowski]

Are you reading a "mirror" image??? "CTK" is an original LT-1 engine. Should it be V0615CTK, then it'd be 1970, June 15, but a reference I have also shows "CTK" for a '72 307ci, '74 400ci or a '78 305ci engine. Can you get a block casting number and date?

 

[mvftw]

I thought the pad had the part of the VIN & the 3 letter code.
I know my '78 is that way.

 

[Tom73]

I thought the pad had the part of the VIN & the 3 letter code.
I know my '78 is that way.

There should be two numbers there, one like V0615CTK, which is the plant, build date, and engine usage. The other would be something like 1Z3S400001 which has the last six of the VIN to match the engine to the car.

 

[Jeffro]

Okay, Now I am really confused. I confirm that the KTC5160V is the ID on the engine number reading from left to right. That would mean that it is the mirror image of V0615CTK.

Is this stamped correctly or is it a bad attempt at a fake stamp?

Where do I find the casting number and date?

The number 3970010 is on the rear driver side but no date.

Any help is appreciated.

 

[JohnZ]

If it's really stamped KTC5160V, it's a really poor re-stamp. 3970010 is the correct block casting number, although that block is very plentiful (7 million of them over 10 years '69-'79 in all cars and trucks); the casting date code is on the passenger side of the rear flange, just behind the cylinder head. The front pad should also have the VIN derivative (like 10Sxxxxxx), where the x's are the last six digits of the car's VIN number, with all the characters exactly the same height and perfectly aligned, in a smaller font than the engine plant code stamp.

 

[born2saw]

Block #3970010 was used from 1969 until 1979. In 1970 if the original block, it would be a 4-bolt main and was used in the 300,350, & 370 horsepower configurations. However, this casting was also used in Chevelles, Camaros, and Novas in 1970. The 4-bolt main version was also used in some trucks.

V0615CTK indicates Flint engine plant, assemled on the 15th day of production in the 6th month of production. CTG is listed as a manual transmission, transitor ignition, 370 hp motor equiped with a Holly 4BBL carburator. In other words, this should be an LT1 motor if the numbers are real. There should be a partial VIN on the pad where you found this number, and according to Corvette by the Numbers, it was a late production, after 3/24/70 so thew VIN should be around 407977 or higher. If it truely is a June production car, the VIN would be between 410652 and 413829.

I have never heard of mirror image stamping, but if you can't see an other numbers on the stamp pad, I would be suspcious and have someone who really knows Vettes well have a look at it.

Hope this helps.

 

[born2saw]

BTW, is there any other indication that this is a LT1? Does it have a LT1 hood? Does it have the horsepower plate under the shifter?

 

[Jeffro]

Everything else says Lt1. Hood, Tach, shifter plate. The number on carb and alternator are correct. Distributor has been changed.

 

[Paul Borowski]

One other possibility is that if it is "a fake stamp", what they MAY have done is taken the numbers off of the "Protecto Plate". These numbers are read on the plate in "mirror image fashion". Or, if you do not have the protecto plate, they may have seen this style and stamped it onto your engine from another "Protecto Plate".

 

[Paul Borowski]

The date of the block is on the passenger side bellhousing flange. It is between the top two bellhousing bolts, to the right of the peak of the flange. The top of the letters face the front of the motor and are done in this style. I just checked my one '68's date and it is D 25 8, which translated is April 25, 1968. A is January, B is February, C is March and so on until December. The next two digits is the day, the last digit is the last digit of the actual year. Your number may say E 15 0, which would be May 15, 1970. This does NOT mean either IT IS the actual engine because here is where GM kinda "HELPED" restampers. Your block being a #0010 block could even be a 1980 block as the numbers were done in the same was probably on all the Flint engines-at least to '82 that I know of. My 1980 Corvette's date on the engine is L 27 9, which is December 27, 1979.

 

[born2saw]

I always thought the letter on the date code indicated the month of production, not the month of the calendar year. For example if the date code is D, that was the 4th month of production not April. In 1970, they coincide because of the GM strike and the first month of production was January, but this was not always the case.

Is this correct or have I been misled??:confused

 

[Paul Borowski]

That was the way the "body build dates" are. "A", first month of production, "B", second month of production and so on. The "parts"-- carbs, blocks, starters, alternators, etc., were dated A=January, B=February, C=March and so on.

 

[Jeffro]

I found the block build date. It's F 11 0 (June 11, 1970. This would coinside with the the VIN number that indicates it is a June production car.

My interpretation is that this is the original block. Records indicate the owner of the car (2 owners ago) have the entire engine rebuild but the block was salvaged and used. My guess is that the mechanic grinded the numbers off in the process and then attempted to restamp but did so poorly.

If this it the original "matching number" block but the stamp is screwed up, how is the value of the car effected? We it value as a true LT1?

Can the block be restamped? Is this wrong or unethical to do if you are 99 percent sure it is the correct block?

J

 

[Jeffro]

Sorry for the crappy spelling. To much caffine.

 

[Paul Borowski]

I found the block build date. It's F 11 0 (June 11, 1970. This would coinside with the the VIN number that indicates it is a June production car.

My interpretation is that this is the original block. Records indicate the owner of the car (2 owners ago) have the entire engine rebuild but the block was salvaged and used. My guess is that the mechanic grinded the numbers off in the process and then attempted to restamp but did so poorly.

If this it the original "matching number" block but the stamp is screwed up, how is the value of the car effected? We it value as a true LT1?

Can the block be restamped? Is this wrong or unethical to do if you are 99 percent sure it is the correct block?

J

Don't forget I said in my earlier post you realistically could have a June 11, 1980 block also. The #0010 blocks were still used then. My guess is someone saw a "mirror image protecto plate style" and did the same to your engine. It MAYBE possible that is the original stamp, but I highly doubt it. If a bunch of cars surfaced with this same style stamping-I'd say it's possible. I think it's a "botched restamp", but I have'nt seen the pad either. I myself DO NOT believe in restamps-really they are a "FORGERY" in every sense of the word. People get to "hung-up" in all this numbers matching deal. If a NON-ORIGINAL engine is RESTAMPED to make it "appear" to be the original one, IS'NT this a FORGERY??? Then car goes to owner after owner, then people start telling others it's the "original" engine the older the car gets. What most people don't realize that in judging most engine points are for the Block casting and date to be "correct", which you have(or it "appears"). I think it's like a 38point deduct out of 4500 if the VIN # does not match. On value? Hard to say, but on a higher end car like yours(LT-1s, L-88s, L-89s, L-71s, ZR-1s & ZR-2s)articles have been written where the belief is 33% of the value of the car can be because "it has the original engine in it". If part of the history of YOUR car included the original engine being replaced, damaged, blown up, numbers grinded off, well, why be ashamed of it??? It happened. I myself would NOT RESTAMP an engine. Ain't worth a lie to me.

 

[Jeffro]

Thanks for the input. I agree that restamping and engine is the same a forgery. I'm going to continue to search for more history on the car. I can live with the fact that it's not "numbers matching" as long as I feel there is enough verification that the car is a true LT1.

J

 

[Paul Borowski]

Jeffro, here's another thing-you may "have" the "original" engine-chances are from what you describe you do. There is probably "other" clues that this is a '70 vintage block-not an '80 block. If you had the oil pan off there maybe clues like 4 bolt mains, type of crank,etc that would almost positively suggest this is the original block. IF the car is a TRUE LT-1, nobody could take that fact away from the car-original block or not. I'm not up on LT-1s, so I can't tell you everything to look for. I think a few important things are the 6500 tach and "single fuel line" with no return line back to the tank. There are other give-away clues, I'm just not an LT-1 expert. You may want to contact the LT-1 registry. They may be able to help you.