[Purdy Swoft]

My heads are all cast iron . I prefer cast iron for durability , A lot of people have been running the Thomas finned aluminum heads for years , the aluminum heads must be doing some good or people wouldn't continue using them . Hot rods with flathead V8s have been using aluminum heads forever . As expensive as higher compression heads are , I want mine to last as long as possible . I've never had a problem with cast iron .