Thanks, hursst. Ok, This engine has this code 17K444516, (9 characters) and it looks like '67 or '77, but the pictures on the site I looked at showed a '67 having a code 7A175291 (8 characters) and '68's with codes 18K23?80, 18B23000, 18Z137810. These having a resemblance to the code on this engine except for the second character being an 8. This is only a block, but it looks old. The pistons have valve reliefs, would a '77 350 had come with these?