Some background: had CA shorty header and catless dp until it gave up the ghost.

Now i have- ZZP Midlength header 3" catless DP and full 3" exhaust that sounds awesome (2 magnaflow 18"longx6"x3"in/out mufflers, one as resonator, other as rear muffler, and 3.5" tip painted black)

i have had header to downpipe leaks for ever and have tried everything

i keep having issues with the 2 bolt gaskets that this header uses

i have tried:
1/2" bolts, new gasket, new gasket with lots of super high temp silicone(the orange stuff)
retorqueing bolts...cleaning flanges...etc...
even replaced the manifold gasket to see if it was the culprit

i am gonna put a new gasket and a little bit less silicone and try that but wanted some opinions

1) do you think i should sandwich 2 new gaskets in there with the silicone?
2) try my other new gasket with no silicone?
3) other opinions?

i was gonna resmoke test the exhaust pipe but cant get up to my previous employer for a little while so i was gonna take the DP off this weekend to see what i can do

at this point i would even try aluminum foil around the pipe to muffle the leaks... LOL JK

ANY THOUGHTS??!@!!

 

Dude i wouldny be filling it with silicon I had a leaking DP gasket problem like you and i gave it to GM and it cost me 200 bucks but it is a tight clean seal. The bolts all need to be tourque and good luck get a TW back there

 

I have had the same type of issues and the next time that I have an issue I am going to take everything to an exhaust shop and have them weld 3 bolt flanges. I think that the problem is that the 2 bolts don't pull the piping together enough and the 3 bolt flange will seal up better.

 

I agree

The silicone is a copper based sealant designed for high temp exhaust
I'm not sure what gm could do that I can't at my shop considering the aftermarket header with the impossible to find gasket