The stuff I have is made by Mr.Gasket, and is 3/32" thick. It is white on one side and has Mr.Gasket logo printed on the backside. I picked it up at NAPA auto here in the states. IIIRC, it is rated to 1200 degrees.

It sounds like you are going to have to pull the exhaust manifold and the down pipe. Oh yeah, more work than you wanted to do.

If you have access to a welder or a friend that odes, I would just weld the down pipe to the exhaust manifold and install it like a header. <img src="/forums/images/graemlins/kewl.gif" alt="" />

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed