I found a set of 13 heads today while going through a bunch of pontiac parts a guy has for sale, they should be a 70 RA III but instead of the raised numbers on the exhaust port the numbers are stamped, a 1 on one side and a 3 on the other doesn't appear to be ground off and stamped, never seen this before and was wondering if anyone has an idea before I buy them. He also has a 64 421 HO short block he's looking for a price on, any thoughts