Numbers matching?
 

Had someone look at my 70 455HO car and tell me it's all wrong, wrong heads (64) wrong exhaust (RA style not logs) and numbers didn't match VIN I know the heads and exh are correct. You tell me if i'm getting paranoid

64s are correct for a 70 455?Tom

64's would be heads for 455 in A-body.
Not sure on the exhaust manifolds.
Is the engine code a YC?
What is the date code on block and date on cowl tag?


:confused:

Exhaust manifolds were log type even with RA.

64 would be correct for a 70 455 HO. 15 is correct for a 70 455 non HO. RA manifolds weren't available on 70 gto with the 455. Why? That I don't know. I put them on my car anyways. Looks the dash vin matches block vin. 3 looks somewhat like a 8 but I think it's all good.

Johnta1 Block is YA

That VIN stamping looks bogus.
 

ALL the 1970 blocks we've ever played with - and that's at least forty of them - were gang-stamped. That one is definitely NOT.

We've never seen a factory-installed block that was stamped like that one is stamped. Ever.

Because of the 'wrong' look of that stamping, I'd be fairly confident that THAT block is NOT the original block to your car.

As mentioned, none of the 455s in 1970 got factory headers - they all got log manifolds.

If I had to speculate, it would be that the original engine in your car expired at some point in such a way that it could not be repaired, so someone swapped in a big car block and re-used the original '64' heads but upgraded the exhaust manifolds.

Does it still have the stock intake, carburetor, distributor, etc. ?

Block casting number 9799140 or 485428 ?

And how does the block date code compare to the head date codes and the actual build date ?

The evidence suggests that whoever told you that it was 'matching numbers' was not being honest.....

Don’t know if this helps or not, but for comparison here are stamps on my 1970 455 HO block

To ease confusion, YA is a GTO 455 HO block on the early GTO's

THAT is what the partial VIN stamp SHOULD look like.
 

Notice that all the digits are stamped in a nice, straight line. Gang stamped.

Mike's YA block was very obviously hand stamped by someone. In the Corvette world, that would be described as a 'forced match'.

Hopefully the YA block is at least a 9799140 casting.

Block is a 140 cast Date: I089
Head : I099 couldn't get to the other one
Intake : I129
Note: This car was ordered by the GM comptroller and delivered to his house not a dealership

Build Sheet

LOL, the days when an AM/FM stereo was more than double $$ of HO option.!

That car has a couple of options. LOL, Marc.

I'd agree, the spacing and the lack of the gang stamp look (even worse these are "stepped"). Also the lack of the circular milling marks (used at the factory to finish the front mating surface) is a big warning sign.

Scrape all the paint off around there and you will see the answer, either you will see the original VIN stamp covered over and or evidence that the surface is ground down or remachined without the factory looking milling marks.

It always amazes me how re-stampers don't even make an attempt to make the stamp look authentic.

True.
 

It's almost like they never saw a factory-stamped block.....