Early 273 intake problems

Jedrattle, shoot a pic of the front of the head where I took my bolt angle pic. Those sure sound like 64-65 heads but the bolt angle is all 66. you can still make them work. just use the 5/16 bolts and hardened washers, you can open the holes a little with a bit. If I had not made my sheet metal intake for my 5/16 '65 heads, I'd trade you straight up for those later bolt angle heads. Alot easier to fab an intake flange with flat bolt faces.