For those that have converted engine types and need exhaust manifolds and such look to the aftermarket headers and pipes for your engine type (VW based, others ?) They have bigger flowing and better formed headers than the stock VW.  There will be mufflers, tips and other parts.

To keep the parts  from melting add CERAMIC COATINGS!

On my stock vanagon exhaust I can now reach down and remove the temp II sensor AFTER a 2 hour run and there is no radiant heat to burn my hand.  Before there was was heat that burned...

Robert