I have been using Felpro metallics without issue. Every time I have checked the bolts have been tight. If I had to change them out- I would go with the coppers that Silver_Dodge suggested just because Iwind it up alot.

As far as torque specs go- If you have headers that allow you to get tq wrench on every bolt, then those headers are either too small are werewere made by one crafty ****. It is best to tighten evenly, sequentially, and as tight as you can go using a standard 5/16-3/8-7/16 wrench using a good threadlocker on the bolts. Then let the headers run through a good heat cycle and re-tighten. Another-then do the same. Then check them after a week. If they're good after that-then check them after two, and so on...

The thing is to make sure they are always tight. If they get loose, the gasket will start to go. Once that happens the bolts will get loose, and, because of expansion and contraction of the flange due to heating/ cooling and vibration they will get looser.

Copper expands more and fasterto compensate.

 

mopowar,

Doesn't retighting the bolt defeat the purpose of the threadlocker? just asking, not flaming or anything. I know you have to keep tightening to keep a good seal.

 

copper it is thanks for all your help everyone

 

What else are you gonna do? When you run through the heat cycles and bolts loosen, you either tighten them or let them fall out I guess.

 

^^^good point!