427 with a 942 casting engine

[Michael H.]

We looked at a 67 coupe S/N 27XX yesterday that had a 942 engine casting with a T1031JF ( 400HP with K19 ) stamping on it. The body build date was Nov 1st. My question is can this casting number be used in this late of a car. Also the engine build date is Oct 31st. and the body build date being Nov 1st it's just to close for me to believe is that possible ? Engine pad was painted so it was hard to get any good pictures.

Mike

[Tim G.]

Re: 427 with a 942 casting engine

It all comes down to the stampings on the pad, but the engine build date does sound too close to the body build date. I'm sure this is a St. Louis car. If the seller has any hope of this engine being considered valid, he will have to strip the paint from the pad and take good photos of the two stamps.

[Michael W.]

Re: 427 with a 942 casting engine

What was the casting date of the block?

[Tim G.]

Re: 427 with a 942 casting engine

I hope the casting date is prior to July of '66. Could be legitimate in theory, certainly nobody would have cared in 1966 if a 942 block was built and installed in a Corvette in September or so.

[Michael H.]

Re: 427 with a 942 casting engine

Casting date was hard to read our best bet was I21 or Sept 21, could not read the last number.

I read in a prevouis thread from John H. that someone he knew had S/N 15XXX that had a 942 casting in that car and was ground out and stamped with 351 over the 942.

Mike

[Michael W.]

Re: 427 with a 942 casting engine

Casting date was hard to read our best bet was I21 or Sept 21, could not read the last number.

Mike

Presuming it's Sept 21 1966, an October 31 1966 assembly date is not too bad. What is the technical reason that this casting number could not have been used past July 1966?

[Patrick B.]

Re: 427 with a 942 casting engine

The 351 casting began on June 1, 1966 or maybe a bit earlier, so even June 66 942 castings would not exist. I have seen 942 castings used on early 67 cars, but the 942 casting number was ground off and the 351 casting number was stamped over it in a distinctive font.

[Tim G.]

Re: 427 with a 942 casting engine

I've seen early '67's with 942 blocks that did not have an altered casting number. I know of one legitimate 942 block with a factory ground assembly date. I've got #350 with a 351 block. I'm sure they were blended in.

[Patrick B.]

Re: 427 with a 942 casting engine

I wonder what was the reason GM renumbered the casting number on some 942 blocks in 67 cars but not bother to do all of them. Tim, what was the casting date of the legit 942 you observed? I believe that casting dates of the altered 942 blocks I have seen were in May. I have also had 858 heads that were ground and renumbered with the 391 casting number using the same stamp fonts I observed on the renumbered blocks. The casting dates of the heads were late june 1966. The earliest head I have seen with a 391 number cast-in was July 9 1966.

[Tim G.]

Re: 427 with a 942 casting engine

I wish I kept track of that, I saw the car about 10 years ago. Now I never let a big block '67 get out of my sight without trying to snap a picture of the pad and find out the casting date.