[Gearhead999]

I've used the "Stage 8" locking header bolts or six or so engines that I've built. They are the best. The bolts don't back out and the gaskets last a long time.

Downside...they are a PIA to deal with in tight quarters. I think they are worth it.

You install them like you would any other header bolt. But, don't put the locks on yet. Drive the car some and then let it cool and retighten the bolts. I go the second time for a week or so, depending on how much driving I'm doing, and tighten them for a third time. Then I install the locks. They're the best. T's up.