dkleather

Don't give up. I got it!! Even removed the "date correct" after NOM engine in my profile. It just means I'll have to put about another 100k on this engine before looking for another. Sounds like fun! Thanks for the info. Dave

DucatiDon

Is this block still available?

JohnZ

Nope, not from GM - it was discontinued over 20 years ago.

DucatiDon

Thanks John, but i meant from the O/P....

7bicks

I have one of htese blocks. It is complete with a fresh rebuild and was bored .60 over. It has been sitting for a few years so it may need gone through just to be safe.

TCracingCA

Took alot of crap! Thus I feel vindicated by the increase of knowledge about this casting number. It shows in one book as a non-application use, just like a particular 1957 casting that also shows no application (GM racing ban!!!!!!!!!!! Exact same years!!!!!!!!!!!!See the correlation!!!!!!!). Our's came with a GM hybrid cam that came in this block that is a cross between a 30/30 and a 140. It reads very strangely with characteristics of both. The block was cast in 1963 but sold CE stamped in 1969. I am sure that he got it thru Dick Valentine (Corvette Racers)- and a dealership that he either owned or was involved with.

PS my opinion and nothing to back it up, this is a funky block and had some special casting and the vent hole in the back. And I apologize for being stuck on this, but the AMA ban was tightened right in Feb or March I think of 1963. I remember reading that the exotic 377 aluminum engine was already out of the plan for 100 car FIA rule. Thus Zora and gang, not GM were headed toward the 327 size, but with a race appropriate block that could hold up. Thus I believe this block casting was begun, but they only got as far as the block and maybe some Camshaft prototypes. Also to talk to the car, I cannot remember reading anything ever that the 100 Car requirement was going to be built to the same level as the Prototype Grandsports. I would have to look and find the Sebring entry papers or any other FIA sanctioned event to see what was presented to qualify and class the car. Thus theory only, a large number of these blocks were laying around until about 1968/69, someone finally decided to do something with them and they went into the parts counter with CE stampings and could be configured to 2 bolt or 4 bolt mains, thus some additional machine work was probably done to them. But the confusing thing on this most recent thread is that some were cast with a built date into the 1970's. Our engine is definitely early 1963. Thus I am going to post a question asking what cam was in the actual Grandsports.

ScottyH

Hello all,
I am new to this forum, but was wondering if anyone could help me out with determining exactly what GM small block I have.
I have a SB with a casting number of:3959512.
It has a date code casting number of:K68
It has a stamping on the deck of:19N550021 V1I19DZ
This is a 4bolt main engine.
I purchased this bare block around 1979 or 1980 from a guy by the name of Joe Stanislaw(AKA Camaro Joe) in Flint, MI. At that same time I also purchased a crankshaft with a 1178 casting number. At the time I had a 1969 Camaro RS/Z28 that I had intended on installing it in. I never did install in the Camaro and I have since sold the car many years ago, but kept the block and crank.
My intent is to sell the block and crank, but I'm trying to figure out exactly what I have for a block, as the casting numbers do not fall into the normal 1969 302 block numbers, and most references I have seen on the internet show the 3959512 block as 327 being built between 62-63.
Any help or advise would be appreciated.
Thanks

rongold

Interesting---It's probably an over the counter engine that was cast on November 6 1968 and stamped with the vin of a 1969 Camaro Z-28--possibly a warranty replacement----BUT, I thought all warranty engines were all stamped "CE".

JohnZ

That's a Service replacement block cast on November 6, 1968, that's been restamped with the Camaro VIN and DZ machine code; the 9512 block wasn't used in production.

Mr D.

TopLS69, could you post up some pictures of this block. If nothing else it would be nice to see one in the flesh so to speak.

Once upon a time I was looking high and low for this 512 block to have my cake and eat it too. Couldn't find one anywhere.

topls69

[IMG][IMG][IMG][IMG][/IMG][/IMG][/IMG][/IMG]

topls69

that didnt work for some reason...I have no idea why I cant use image shack on this site, but it works everywhere else.... P.M. me and Ill send em your way, or tell me how to post pics on here.

DucatiDon

I also have been looking for one.....

Revfan

Topls69 I get the assist!
you had an extra "/" at the end... here you go




I don't know if I'd trust these guys to work on my transmission though...

topls69

revfan thanks for the assist!! yeah the last pick is of some of my musky fishing buddies from a tournament, not the guys you want working on your vettes. this block is just as it came from the factory other than i ran it through my shot blaster.

DucatiDon

it looks like its plumbed for pcv breather on the back...is that correct?
journal and bore size?

topls69

Yes its machined for pcv/road draft. Standard 4.00 bore, large journal. Never blown up or damaged, I'm still deciding what I'm going to do with it.. I have matching heads and a bunch of other parts to put something nice togather with it if I ever get all my big blocks I'm working on done. Probably going to make a nice stroked street motor out of it...someday.

ScottyH

Thank-you guys for the info. Much appreciated.
Anybody interested in the block or crank can email me at: choochoocharlie65@hotmail.com
Scott

topls69

Decided I'm not going to do anything with that block.. I just listed it on eBay, just search 3959512.. Low reserve.

SISSYG

hi anyone know the replacement casting number for the 512 block?
the one given by gm..