I used FelPros marines on my heads.Mine were the first sets.Id have the valves checked because the valve job is OK but not great.Mine needed lapped.What cam are you running>My .588 we upgraded the spreings retainers and locks.Went to 10 degree pieces.With a smaller cam and auto they would have been good to go.Never trust an out of the box part.Mine have been on over a year and no problems.Rocky