So I have thorley header that the flange and pipe welds to it are not flush... I got this REMFLEX gasket and like a champ, FIXED! These gaskets compress 50% and are good to something like 3000* I think it said. I guess they've been around for like 10 years but just now started to advertise... So, if you have an exhaust manifols leak at the head, get this gasket! It was 34 bucks after shiping and the stocker ones cost me 30+tax! Just thought I'd share my excitment....