can you run severe duty stainless valves in a boat or do they got to be inconal??????

You can run them, but you would better off with inconnel exhaust valves.

Like said stainless is fine, intake esp, but it is better to run a inc exhaust valve..

John jr

Zeke,
It really depends on the horsepower output of the engine. Most of the lower horsepower Mercruiser engines have nothing more than stock GM automotive & truck type valves in them. The higher HP Big Blocks have Manley severe duty intakes and Manley Inconel exhausts. If you are just doing a mild upgrade, almost any decent Stainless valve should be ok. I would stay away from the "cheap" $8 stainless valves. Ferrea has a very good line of valves that are in a "medium" price range. Thier "severe duty" valves are also about as good as you can get.

Hope this helps,

Bill Koustenis
Advanced Automotive Machine
Waldorf Md