I used 3" schedule 40 pvc. then i put to coats of flat black primer.
what kind of paint did you use? u think ceramic header coating would work?

 

That sounds like a good idea, if it will stick.

 

never heard that what it do to the heads

 

I don't know exactly but I have heard that PVC is not good. Not only the vapor that could potentially go into your engine (not being pure oxygen isn't good) but also the same problem K&N had with residue coming off the interior of the pipe. There are other ways to make a home brew kit without PVC. But again, that would be after a long exposure to high heat and over the course of several years.