Edelbrock / RHS heads, or go BIG block and put it to bed!
Remember that you can get RHS heads from other places than IMM, I am sure they are great, but why is that the only place people here talk about getting them from. I don't think the average motor needs 300 dollar behive valve spring or ferrea valves. If your springs and keepers are still close to being new why not re use them if they match your cam, isnt there a place local to you that does performance valve jobs?