ok so i checked again and it is clearly a 3 not an 8?? so its 3994258. on the block there is also c 1 2.. so the question is ... was it March 1 1972 or March 1 1962... how do I find out and where there any differences between the two?? i am truly unsure and cant find this cast number anywhere... also it looks to have been rebuilt fairly recently and a new cam installed. I am really starting to wonder if I will need to do to much to it. Interested to open it up and see now.