I am in the process of changing my twice leaking felpro 1406's with percy's dead soft with ARP 1" bolts. I noticed that on both sides, on the bottom part of the middle two primaries there was a lot of black carbon buildup (on the old gaskets). I am making sure that these Percy's gaskets will be aligned perfectly (the felpros were too) but what would cause this?

I was thinking however, does it make a difference is the y pipe is hooked up?? It is kinda pulling on the header. I jacked it up a tad bit and that helped but the header is being tugged by the y pipe.

Anyway, I just wanted to know if anybody had this problem and had insight.

 

check to see if the header flanges are warped.
try unbolting the y pipe and then tighted the headers up.
it sounds like you may have a warped header.....
jesse

 

I somehow doubt that both headers would be warped in the same spot. Also, the carbon buildup was on both sides of the gasket. That leads me to think that the gasket was not down all the way and it overlapped or something. Either way I'm almost sure that these Percy's will work well. I'll post whether or not it fixed this problem. I spent a lot of time squaring everything up.