I have done a search and found that this is the most reccommended gasket for a header install (Felpro 1406). My question is what material are these gaskets made of, and do they "crush" when you tighten the bolts up? Also, do these fit the ports on the header itself pretty well (Hooker LT)? One more question: did you use RTV on the gaskets and why or why not did you do that?

 

There made of graphite, and I would assume that they would all most have to crash a little when you tighten them down, mine fit the ports on the headers fine, and no rtv is really needed, mine dont leak with out it anyways.

 

I just put these gaskets on mine with SLP shorties. They seem to be much better then Mr. Gasket ones I used before (these laster a week). Haven't had any problems yet and seem to be as good as the SLP gaskets which came with my headers.

 

These gaskets are awsome, i have had them on my Z with TPIS LT's for a year and a half with no prob. I just took them off and the gaskets still look like new. I was amazed. I will be using fel-pro gaskets for years too come.