Join Date: Jul 2011
Location: The State of confusion
Install your new crush gaskets into the head first. As the proper torque is applied to the exhaust flange bolts, these gaskets will seal the Power Cones as well as the exhaust.
I've never found the need to double up on any gaskets, nor have I ever encountered any leaking doing it the way I mentioned using the single gasket.
Not knowing if you've added a EFI Tuner, or the exhaust doesn't have any baffles, mufflers are all suspect and may cause your decel popping problem.