I have a set of SUMMIT header collector that leak
at the gasket.I changed from the paper to a soft lead, still leaks this is the type were if you do not line up the collector and the header just right it leak between the bolt to bolt distance
i have tryed to tighten them to the point of no movment but still leak . what can i do ?? will stacking two gaskets help??

You could definatly try stacking two gaskets.

Make sure you tighten it incriments all the way around or the flanges can warp.

I've had great luck with the Napa nitroseal collecter gaskets.