I'm building a few 350 260 horse Merc motors.
It seems that with the 20 + sets of heads I have, all need major work. Some heads were car heads some marine. It seems that all the boat heads need exh. seats. This is expensive. It also seems that most have excessive valve stem clearance, which I repair with bronze k-line guides. Out of all my big block head work I have had much less trouble. I use the positive seals and trim the guides for them also. I don't want to do bad work such as sinking the valves. Also the older heavy casted heads should have hard seats installed. The only real similarity between the big and small block marine heads is that I end up tossing the exhaust valves out due to excessive pitting. I want to build stock motors that stay together , does anyone have the real answer to this head issue. It has to be profitable! I am starting to feel that I should just marinize new crate motors due to the labor and costs involved , but I feel that I can build a better motor. BBB ,
ps. Thanks ahead of time.

Slap a set of AFR's on those motors and you will be happy

If you are looking for a quality head at a good price look into the World prducts SR head. They are a tough piece and you can get them with1.94 or 2.02 intakes. The 1.94 head is more than enough for the 260 horse motor and I think they are around $295 a piece.