I have 2 sets of them stamped the same.Mine are rolled over to 16 degs.Lay your head on deck on table with valves in them and measure what you have for angle.Its been yrs since I ran them but iirc they have diff spacing than 363 heads and need pistons designed or flycut for spacing diffence.I think cfe did ours .
These haven’t been rolled much if any and are 2.150 intakes and 1.600 exhaust. Looks like theses definitely need new valve guides because of cracks at the end and the valves look sunk pretty far but im not a head guy and proactive a light deck. Just wondering if its worth investing a $1000 or so into these or am I wasting my time. Going on a 421 or 377 circle track modified.
Put 2.180s in and recut seats .With some attention they would make decent power for you for that money spent.You push guides out you need to recut seats anyway.As hard as it is to buy new ,probably better to fix those.
You will need to open chamber for bigger bore.We ran our engines in a boat.Later we cammed and went after total engine combos and each engine went in dragsters at 4.155x 3.550 stroke.We made right at 900 hp with each of them.