Need help with casting number!

[L30M20]

Hello everyone, I am looking at a supposedly L-78 69 Camaro, with a build date of 11b-X-66 code (late 69 car.) It has the single fuel line, 6kred/7k tach, "854" motor casting number,w/ J-20-9 cast date. Can not really see the pad to well, looks like T10 or 11, can not see the rest of it yet. The question is, I thought a "272" casting number block was used on all L-78's, am I wrong, since this a late car, did they switch to a different casting number? Thanks to all, Craig

[Musclecarkid]

Craig, The #272 casting was used up until around May/June of 1969, after that the #854 casting was used. Kid

[nuch_ss396]

An '854 would be the correct block for that particular car.

Question I have is what would the bore be? 396 or 402?

Steve

[akcamaro]

I've never heard of a 3969854 that wasnt a 402 bore, but I'm no expert.

[Mr70]

That block doesn't sound authentic to that Car.
June of 69 was the cutoff for the 396 #272 block.
After that,the newly anticipated 1970 model year #854 block started being installed in the few remaining 69 builds.It was now a 402 CID due to a .030 overbore,that carried the letter C in front of it's earlier two letter engine suffix code.
I too have only seen this in 402 CID.