Im about ready to get myself a DC 4-1 header, but its offered with a gasket and a flange for extra cost. Im guessing that the gasket goes betweed the header and the engine, and the flange goes between the collecter of the header and the cat, but doesnt the header already have a flange on it?

If i just order the header will I be alright or do i need the other parts also for it to bolt on correctly?

 

No it doesn't. Get the flange.