CLASS RACER FORUM - View Single Post - Mystery BBC head casting number 1X157129AC

Rich Biebel · 01-30-2010, 08:55 AM

My best guess is they are aftermarket heads. I have never seen any Chevy head with casting numbers like that. GM as far as I know only used numbers in their Chevy castings. Many heads have a seperate letter cast on the head but it was seperated from the actual casting number. An X was found on some small block heads as well as some other letters.A Date is usually also cast on the head if it's OEM.

01-30-2010, 08:55 AM	#9
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,315 Likes: 25 Liked 544 Times in 213 Posts	Re: Mystery BBC head casting number 1X157129AC My best guess is they are aftermarket heads. I have never seen any Chevy head with casting numbers like that. GM as far as I know only used numbers in their Chevy castings. Many heads have a seperate letter cast on the head but it was seperated from the actual casting number. An X was found on some small block heads as well as some other letters.A Date is usually also cast on the head if it's OEM. __________________ Rich Biebel S/C 1479 Stock 147R