Count me in the group that simply took my Stealths out of the box, changed the valvesprings to the ones that came with my cam. Also added 10* locks, and bolted them onto the car. Went a decade with Zero issues. Finally pulled them a couple of years ago and sent them to MCH for a full CNC port and prep. Everything with that process went great, now flow 320+ (according to MCH). I have never had an issue of any kind with mine.