454_71Stingray

I have a 0010 4 bolt block that has a june 68 casting number. Since htese blocks were usin a couple different things, Vetts and Trucks at least, is there a way to definately tell if it is a corvette block? I took it out of my 71 so I could truthfully say that it came out of a corvette, I just couldnt say that in good conscience. I cant find any vin #s on the thing anywhere either, might be looking in the wrong place?

Entropy

Did you look at the front passenger side pad of the block (in front of the passenger head). If the block hasn't been decked, there should be a stamping there that would indicate what the block was for. You'll find what the numbers mean in any corvette black book.

trw

mapman

Appears that partial VIN use began in 1965. See FAQ on matching numbers.



http://www.classicchevy.com/rest_questions.asp

luerja

Could have been a GM service replacement engine? maybe check the heads and see if they are correct numbers?

Engine Suffix ID Numbers
HE: 327ci, 300hp (manual transmission)
HO: 327ci, 300hp (automatic transmission)
HP: 327ci, 350hp (air conditioning, manual transmission, power steering)
HT: 327ci, 350hp (manual transmission)
IL: 427ci, 390hp (manual transmission)
IM: 427ci, 400hp (manual transmission)
IO: 427ci, 400hp (automatic transmission)
IQ: 427ci, 390hp (automatic transmission)
IR: 427ci, 435hp (manual transmission)
IT: 427ci, 430hp (L88) (aluminum heads, manual transmission)
IU: 427ci, 435hp (aluminum heads, manual transmission)

Block ID Numbers
3914678: 327ci, 300hp, 350hp
3916321: 427ci, 390hp, 400hp, 430hp, 435hp
3935439: 427ci, 430hp, 435hp

Head ID Numbers
3917215: 427ci, 390hp, 400hp
3917291: 327ci, 300hp, 350hp
3917292: 327ci, 350hp
3919840: 427ci, 435hp (iron heads)
3919842: 427ci, 430hp, 435hp (aluminum heads)
Cylinder Head Casting Number:
The cylinder head casting number is usually found on top of the cylinder head in between two valves and the rocker arm studs.

Cylinder Head Casting Date:
The cylinder head casting date is usually found adjacent to the cylinder head casting number. The casting date code is an alphanumeric sequenced number. The first digit is usually a letter which specifies the month that the block was cast. Some casting dates have been found with all digits being numbers, the first of which corresponds to the month.

Cylinder Head Casting Number Month Codes (1st Digit)
A - January E - May I - September
B - February F - June J - October
C - March G - July K - November
D - April H - August L - December

Two main plants were casting Chevrolet engine parts during 1968: Flint, Michigan and Tonawanda, New York.

Example: Flint Cylinder Head Casting Number - D 19 9


D: Month = April
19: Casting Day = 19th
9: Casting Year = 1959

Example: Tonawanda Cylinder Head Casting Number - D 19 59


D: Month = April
19: Casting Day = 19th
59: Casting Year = 1959

Corvette ED

GM started putting the Vin's on Corvette engines in the second half of the 1960 production run. All 1961 to 1882 Corvettes had them.

Paul Borowski

...1882 Corvettes Ed?????

ddecart

If it's a 3970010, it's NOT a '68 block. It's probably a '78 block. If I remember correctly, they started production on the 3970010 blocks sometime in 1969.

stingr69

I agree - it is probably a '78 block. -010 blocks were not produced untill later '69 model year.

Also, while VIN derivatives were stamped on all car and light truck engines, they were not stamping heavy duty truck engines. It is possible to find HD commercial truck engines that have broadcast sheet codes/assembly date (plant code with month/day code and engine application suffix ) but no VIN derivative. Some plants were stamping VIN derivatives down near the oil filter pad when the alternator moved over to the passenger side of the block. That practice varied depending on where and when the engine was installed

-Mark.

454_71Stingray

Great! Thanks for all the info. I have the engine sitting under my bench at home and I want to tear it down and make a 383 stroker out of it. It is kind of pieced together from several cars the intake is a 68 Corvette (According to the NCRS book) the exhaust manifolds are from a 62 and the distributor was from a 62 FI, mechanical advance type. Heads are just some old mis matched set of 1.94s. but it is a 4 bolt main so thats the good news.

RHD '68 L89

If the dizzy is a FI unit it should have the fuel pump drive on it. Should be worth a few dollars and then upgrade to a more modern unit.:nod

ddecart

Make no mistake, that's a very good block. A good, seasoned 4-bolt main block is hard to beat.

I think that's a relative of the block in my car. 0010 block from a '78 full size truck if I recall correctly.