doridori23 wrote:Then Helicoil is the way to go. Contrary to popular belief a helicoiled hole is stronger than the original no matter what material is was tapped into. The reason is a helicoil allows for true torque on 100% of the threads. Need proof? Other than going to helicoil's site every single bolt on F1 motors (Honda because Cosworth is now a whisper in the wind) is in a helicoiled hole. Most funny cars, rail cars, sprint cars, etc etc etc are all the same way. A Boeing 747 has over 250,000 Helicoils from the factory!
+1 I work at Pratt and Whitney, and all I hear all day is helicoil this, helicoil that. I was talking to this dude who builds race engines for motorcycles, and he says the first thing they do when they get these brand new motors is take them all apart and helicoil every hole.