Quote:

It's important to get the flanges as straight as possible.If it keeps leaking try Permatex Ultra Copper Silicone.Put a heavy bead on the flange or head,bolt the header snug,let it sit over night to fully cure then tighten.Check and recheck the bolts after a few heat cycles.



thanks, I used the Fel-Pros w/ ultra copper on both sides. My mistake might have been not re-snugging after a few cycles. I had maybe 100 street miles and 5 runs on them before the went. How much flange do you need for a good seal? These seem to have about 1/16-3/32"