I don't use em. I haven't found any that were worth a damn. Have the header flanges surfaced on a sander by a reputable machine shop. Get yourself a tube of "Ultra High Temp" RTV". It will say on the package it's usable for exhaust manifolds. Put a nice bead all the way around the port, mount the header wiping any excess off with a rag. LET IT CURE, at LEAST 24 hours. Should be good to go. We have been doing this on the race cars for YEARS with good success. The trick is making sure the flange is good and flat. But HEY,,, that's just ME! Bruce Hevner _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list