Engine assembly was started today but a slight issue has arose. Now there are only 4 head bolts. So I thought just buy a new set. Cannot find anything for the 1974 F.5. Everything is 1975 2F and later. No problem I said to myself. Went a removed a couple bolts on the 1972 F that I have. Oops they are too short. The bolts I have are 6.25" over all length. Are the 2F head bolts the same length?