Thread: Small block engine identity?

Tweet

Have an old 4 bolt main block looking to know what it actually is. Tried several id sites and pages but this engine isn't in any of them. casting GM 3970010. Date code D208. engine code V0516(T or1)DB. engine block VIN code is where I'm confused it's C8Z192394. What is this engine block and what did it come out of?

3970010....302.....69....4 bolt mains...Z-28 Camaro
3970010....327.....69....2 bolt mains...Trucks and industrial
3970010....350...69-80...2 or 4 bolt mains

TDB shows as a 307, you will need to give us more specific info on the letter stamping. Clean it off really well with a nylon bristle brush such as a toothbrush and solvent.
.

It is a TDB suffix block so the engine id code is v0516TDB. However, it is a factory 4 bolt main, so it can't be a 307 or a 327. It is definitely not a dz motor. No dz anywhere on block. Therefore it has to be either a block cast in 68 or 78 with date code D208. Other puzzling thing to me is the engine serial/VIN #s C8Z192394. The "C" designation in the first position seems strange to me as well. I thought it was supposed to be a "1". Yes I know chevy used C to denote factory replacement blocks but the following numbers are not a GM block part number so it has to be the vehicle VIN sequential number. Would really like to find out whether it is a 1968 or 1978 cast block and maybe narrow down what vehicle model(s) it came from.

On one site, TDB says 1972 307 C10 and C20
On another site, TDB says 1980 C10 and 1500 truck with no engine size designated.
.

I come up with 69 - 302 4 bolt Z28 hope this helps

So,my lifelong poor luck has maybe surprised me for the first time in my life? It did come with a forged steel crank that I gave away a couple of years back. If it is a real early 69 z28 block then it will be for sale. Surface rust only from being in dry storage after .030 bore job. I never honed it out to size as I didn't have the pistons or rods. Anyhow, the amount of rust that is in it will come right off in a jet washer before honing bores out to size. I left .004 for honing purposes. Interesting thing to note is he claimed it was a 1968 327 4 bolt Corvette block (fabled?). Told him it looked like a common 350 4 bolt block and steel crank to me.Thanks for the info. Can anyone else confirm this for me?

Originally Posted by cffisher

I come up with 69 - 302 4 bolt Z28 hope this helps

could you point me to where you found this information?

Home - EngineLabs here ya go

thanks for the information.

Interesting note! In the last few days I have learned, through GM, that prior to 1972 most, if not all, of the records from the GM engine manufacturing plants were destroyed on a regular basis as they did not have room to store them. GM corporate was not required to do so and they generally did not. Therefore, this begs the questions, where did the plethora of information come from for engine stamping numbers and how reliable are these sources without GM's ability to confirm? Additionally, read an accounting of GM engine plant operation it was such that sometimes they would just put blocks in the assembly line randomly regardless of the casting numbers and engine id #s. The engine serial/VIN#s were stamped at the vehicle assembly plants as they were installed into the chassis, again not always mindful of what casting or engine id#s were on the block. Therefore, unless anyone were fortunate enough to match an owners specific car to the serial/VIN combination and researched the actual vehicles installed original equipment a person could not identify, without at least some doubt, what those blocks were used in unless some other organization/persons recorded this info??? the question marks are tri-purpose; 1 my conclusions are just logical thoughts, to express my confusion, and to display my extreme curiousity with this process!

Four listing for TDB
Truck 71 307 200hp manual L-14 2bbl C (2wd) 10,20,30 series
Truck 72 307 135hp manual L-14 2bbl K (4wd) 10,20 series
Truck 80 350 170hp manual LS-9 4bbl C 10 federal emissions
Truck 85 305 160hp manual LE-9 4bbl CK 10, 20, 30 Federal and Hi altitude emissions

I had an 85 K10 with the LE-9 motor.....what a dog. Replaced it with a
350 and it got better gas mileage and was much quicker

yes my 85 bought new with 305 couldn't pull anything and would not back up a trailer .. crap engine

More deep thought here (LOL)! As the id numbers on the block I have possession of do not conform to the standard stamping process identification lists available - ie. odd serial number letter combination. I have come up with a logical possibility, among many, that due to the strange prefix of C by itself and not a 1 or CE that this may be a block that was produced to be installed sometime after April 1968 in a Canadian vehicle. Can't be newer than 1972 as Feds passed laws making the automotive manufacturers standardize, and maintain these records.The stamped date code confirms it is either a 1968 or 1978 engine block and policy and law says it cannot be a 78 piece. The engine id being V0516TDB it narrows down the production facility and a May 16th date,showing either a late 1968 or 1969 vehicle? The TDB is where much more confusion comes in as GM didn't use the 3 letter suffix until 1970 but it would denote, from what I can find, makes it either a 302, 307, 327, or 350. This is definitely not a 307 as no 307 4 bolt blocks were ever produced nor was the 3970010 block used in the 307. That leaves 302, 327,or 350. Also, addressing what is known about Chevrolet small blocks it is extremely doubtful that it is a 4 bolt 327, because as far as I can find out they are only a myth and if produced they were most likely were found in Canadian trucks. Would make sense with the "T" designation in the engine code that it was destined to be installed in a truck. Allowing for a Canadian installation, I can understand the differences in the serial/VIN number format. Did they use a different suffix format in the engine code as well? I doubt it. So, is the suffix for this block actually just DB and the preceding T mean something else? I don't know as I can't find any reference for a DB suffix for a small block! Therefore, I can only conclude that this block is either a 350 or 302 4 bolt main engine block. Now back to the serial/vin code- what does the "Z" designation? Can't find any reference to that either. So, I can't reliably identify this engine block. Another thought is did someone change/stamp the engine id code to match their car? That is a possibility but once again doubtful as when I acquired the block it was standard bore and I can't see anyone doing a matching numbers car/truck without remanufacturing the engine. That just doesn't make sense to me. As far as it being a 302 block who knows? Like I said the numbers don't conform to what I've learned anywhere about the Z/28 Camaros. However, with the questionable numbers and sequences as they appear on this block and GMs inconsistancies in identification processes prior to 1972 and possibility of a Canadian installation it still doesn't rule out the 302 block. Any Canadian afficianados out there? While my wallet would love if it turned out to be a 302, I am still very, very doubtful that it is such a find. However, as a retired former owner of a jobber automotive machine shop it is possible as thousands and thousands and thousands of these engines passed through my shop. My present conclusion is the only way to know would be to find the vehicle that has the matching VIN.

Never thought that the T_ _ would be indicating truck but I looked in the book....there were perhaps 3 or 4 Camaro codes starting with a T but all others ARE truck applications. You don't have a 302 block. But what difference does it make? Other than The ChevyII block differences and 4 bolt mains vs 2 bolts, they blocks will work. If you are racing, you wouldn't be playing with a stock block. I learned something today about the T prefix....thanks

Originally Posted by robot

....But what difference does it make?

Not to rain on your parade, but I had the same thought. The big thing today is doing LS swaps, not going back to Gen 1 SBC's. Even if you could prove, drop dead certain, that your block was a '68 or '69 302 Z28 origin, I don't see anyone really being that interested in a 50+ year old bare block, no matter it's history. There's just too much stuff going on today with the newer engines.