I've developed an exhaust leak since the Radix install. I had issues with the header flange gaskets on my last truck. So this time, I bought some thick aluminum gaskets for the 3 bolt flange. They are supposed to stop the leaking issues you have with paper and fiber gaskets wearing down or blowing out. I've had them on for nearly a year without an issue. Got a problem now though...

I guess with enough pressure and heat, the aluminum gaskets melted and blew out. When I got under there to check them, I immediately noticed they were warped. Need to find something better now.

 

I use copper 3" gaskets. They are called "copper-seal" and made by Mr. Gasket. The system I built is flanged in 4 places on each side with one more for the balance pipe (9 gaskets total) and I have no leaks. I cannot say my catalytic converters have done so well though, the elements completely disintegrated. I have observed the cats glowing brightly enough to read by and yet these gaskets hold.

 

Something I saw on TRUCKS! recently was a system of interlocking braces that fit on each side of the flange, to resist warping. The thick backing plates looked like an ingenious design.

 

looks like you did away with the tog flanges
and went over the crossmember
nice
I was thinking of that got more pics?

 

Mine are ASM headers that have been expanded to 3". I had the copper seal gaskets on first, but I couldn't get a real tight good seal with them. There was always a minor leak. I agree though, they would have held up better than these aluminum ones.

I don't have cats. I think when I put some on, I'll place them further down the exhaust stream after the X pipe.

 

wont that hurt power?
I think I read something about the new vettes having the cats
closer to the exhaust manifold for that reason.

I may be wrong though

 

I used the metal gaskets and have been working good.

 

V-Flanges and V-Clamps are the best out there in my opinion.

 

I've been trying to find some ball/socket 3" flanges, but haven't had any luck. I'll look up the V flanges.

Having the cats close to the headers gets them hot sooner, which is good for emissions. I'm planning putting them after the X, that way they get equal pressure and if one fails, exhaust will still have a path out.

 

V band would definitlay work. Those three bolt flanges have been used forever, They work great for awhile then over time you have to keep tightening them. Then they warp and will never seal again. I would go with either a V band or a "capture brass ring" with thick flanges, 3/8 to 7/16 should be fine.
Ricky