4-bolt 350

[Space Cowboy]

Hey Vettehead... I found this site that defines all Chevy spec. codes... even the KH that I have.

http://www.prestage.com/Tech+Info/Engine+Specs/Chevrolet/Chevrolet+Engine+Codes/default.aspx

Would you mind taking a look at it for me and tell me what all its saying. It still really doesn't define how many bolts.
Thanks

 

[Vettehead Mikey]

Strange... I was curious about other numbers on the block. I look on the rear driver side of the block and had large numbers molded in... 3970010. When I looked at various searches all of them stated. 3970010....350...69-80...2 or 4 bolt.

So I guess I'm back to asking how do I determine if its a 4 bolt?

Sorry folks!

That casting number is very common and was used across the Chev car line for the years stated, not just Corvette. It's not a correct casting number for a '68 Vette obviously. The strange thing is I see no reference anywhere to that casting number with the engine code KH. If you could supply the casting date of the block (passenger side of the block at the mating flange with the bell housing, that would give another clue.

In any case, I think you'll need to pull the oil pan off if you want to be 100% sure the engine is a 4 bolt or not. I don't know why the buyer is making an issue of this, 4 bolt has very little practical implication on the street.

 

[Tom73]

Okay... I found the numbers on the passenger cylinder head. There were actually two sets of numbers, one on top of the other and one set was a different stamp type than the other.

The top set = VO3256KH (I'm guessing that the second character is the letter "O", and not the number zero)

The bottom set = 17D475048

Strange... I was curious about other numbers on the block. I look on the rear driver side of the block and had large numbers molded in... 3970010. When I looked at various searches all of them stated. 3970010....350...69-80...2 or 4 bolt.

Looks as if we have a conflict here. In the VO3256KH the KH indicates a 66 327ci/350hp Vette engine. But the 3970010 is a 350 block used from 69 through 80 in all kinds of cars, including Vettes, and in both a 2 and a 4 bolt config. Normarly for a 3970010 block I would ask for the stamp pad number but that wont work in this case and it is not a 350ci engine stamp number.

So the only real way to know is to drop the oil pan and look

Just as a side note, no 68 small block vette had 4-bolt mains from the factory. The 68 came with a 327. Chevy did not start using 4-bolt mains on the small block until certin models of the new 350 came out in 69. So if a 68 or earlier Vette has the original small block, then it is a 2-bolt main. Once they start swaping engines then all bets are off

EDIT: One additional thought. Could the stamp pad number be V0325CKH???? If so that would be a correct stamping for a 3970010 block. The CKH suffix was use in '73 and 74 on 350ci engines. In 73 it was a 350ci/175hp engine with 4 spd used in F, A, and X bodies; then in 74 it was a 350ci/160hp with auto or manual used in F, A, and X bodies. Being only the 175 or 160 hp versions of the engines I would suspect that it is only a 2-bolt main engine.

tom...

 

[JohnZ]

Okay... I found the numbers on the passenger cylinder head. There were actually two sets of numbers, one on top of the other and one set was a different stamp type than the other.

The top set = VO3256KH (I'm guessing that the second character is the letter "O", and not the number zero)

The bottom set = 17D475048

Can anyone look this up for me and what is the difference between the two sets of numbers.

Thanks!

The VIN derivative says it's out of a '77 passenger car built at Doraville, Georgia, and the engine plant stamp is most likely "CKH" (not 6KH), which was a '77 350/170hp 4-barrel used in passenger cars, Chevelles, Monte Carlos, and Novas.

No way to tell whether a 350 is a 2-bolt or 4-bolt without removing the pan, but the "CKH" engine was definitely a 2-bolt.

 

[Space Cowboy]

JohnZ & Tom73,

Thanks for the information. Let me see if I can clear up some of the confusion. The 68 Vette used to have a 427 block in it. We're not sure due to lack of historical information, but we think a previous owner blew it out and dropped in the current block. Therefore the VIN derivative on the front passenger side header of course doesn't match the actual body. Tom73... you are correct in that the stamp pad number is V0325CKH, not ...6KH. It was late and I misread the character I guess.

Now here is where I'm getting confused. Vettehead state that the numbers mean March 25, 1966 when the engine was assembled. Is it possible that being I misconscrewed the C for a 6 lead him to the wrong information? And the other confusing thing is that the web site that I found that listed the specs for block stamp 3970010 stated that it could be a 2 or 4 bolt. So JohnZ... whats is it about the code CKH that determines if its definitely a 2 bolt as you've stated? Is there anywhere on the web I can look into this?

Thanks guys... you've been very helpful. I hope this cleared up some of the confusion. I should've given more detail on the vehicle.

DNewton

 

[Tom73]

Now here is where I'm getting confused. Vettehead state that the numbers mean March 25, 1966 when the engine was assembled. Is it possible that being I misconscrewed the C for a 6 lead him to the wrong information? And the other confusing thing is that the web site that I found that listed the specs for block stamp 3970010 stated that it could be a 2 or 4 bolt. So JohnZ... whats is it about the code CKH that determines if its definitely a 2 bolt as you've stated? Is there anywhere on the web I can look into this?

The stamp pad number (V0325CKH) translates as V=Flint engine plan, 0325=March 25th, CKH is the engine usage code. Look on the block on the other side from the casting number and you will find a date code. That will give you the year. It will look something like A103 for Jan 10, 73.

The '010 block was used as a 2-bolt and a 4-bolt depending upon config. For example, in the Vette in '73, the base L48 was a 2-bolt main engine while the optional L82 was a 4-bolt main engine. So for an engine rated below 200 hp it would stand to reason that they are all two bolt. The higher HP performance engines got the 4-bolt engines. Also it is very easy to turn a 2-bolt block into a 4-bolt block, just drill six more holes, add 4-bolt caps, then aline bore the mains. (note: only the three center caps were 4-bolt, the end caps were 2-bolt).

But for the street, having 4-bolt mains is not a big deal. The L98 in the C4's were only 2-bolt engines.

tom...

tom...

 

[Space Cowboy]

Thanks all... I think that covers everything.

 

[Vettehead Mikey]

JohnZ & Tom73,

Now here is where I'm getting confused. Vettehead state that the numbers mean March 25, 1966 when the engine was assembled. Is it possible that being I misconscrewed the C for a 6 lead him to the wrong information?
DNewton

Yup, it's not hard to get me confused. The supposed 6 made me think that his was the year of manufacture, even though that's not a typical part of the engine plant stamp. The fact thats it's an 0010 block precludes it from being a '60 era engine and the CKH nails it down tight. Sorry for the red herring!

Well, at least we chased off the hijckers!

 

[Stallion]

He didn't - he was talking to somebody else (hijacking= rude)

Wohhhh, wait a minute. Somebody asked about their '78 L82, so I simply told them that it was a 4-bolt. I guess I didn't make it clear who I was talking to. Sorry.