What size exhaust flange gaskets?

[jjue]

I'm about to order the ceramic coated FMS headers for GT-40P heads, and I was wondering what size gaskets are on the collectors and other exhaust flanges leading up to the mufflers.

I figured that while I'm trying to fix my exhaust leak, caused by the headers that I might as well eliminate all possible leaks. I'm thinking maybe copper gaskets throughout.

 

[Alec]

I know for the 4.0's the only gasket I could find were Motorcraft since the shape was highly specific.

 

[james t]

it doesnt use a gasket on the collector. its one of those weird-ass knuckle flanges, and it seals itself when torqued down.

EDIT- i see you have the P heads. i was refering to the regular GT-40's, but i still think what i said will apply to the P's also...

 

[jjue]

Yeah, I found a decent picture, and you're right, it's a similar concept to brass compression fittings. I also noticed that it's a 2 bolt collector flange rather than a 3 bolt like most, hence maybe the funny looking fitting that it is. So far, I'm guessing that my exhaust flanges are 2-1/4", so I guess that I will be order a few of those as well. If I don't use them, I know a few who will use them. I'm just trying to solve the exhaust leak for right now.