Sometimes high performance headers aren't always that easy to seal. We at LRS have dealt with this many time and came up with this Extreme Exhaust Gasket kit for 1993-1995 Lightings running a 5.8L based motor.
These kits Include a set of our premium Copper header gaskets and a set of (16) locking header bolts. The Copper header gaskets are designed for high performance applications and the Header fasteners absolutely, positively will not back out. Using these locking fasteners Eliminates the need to monitor and tighten bolts regularly. They are made of Grade 8 aircraft quality bolts that are made right here in the U.S.A.!
Working in a customer service oriented job I can truly appreciate minute by minute notifications and incredible customer service. I am building my seventh fox and have dealt with every known distributor on the planet and LMR is by far the most efficient and thorough company I have dealt with.(twisted wedge top end kit and supporting equipment project starting this week)