no gaskets are needed on stock pieces, I just went through this whole problem . I tig welded them and too much heat built up and warped the flange .I bought new headers from postons they are nice headers but stock crossover was a pain to make leak free. So I bought passenger side header and two piece cross-over all jet coated. If you weld the headers yourself use a mig welder use mild steel wire. The header is 304 stainless control how much heat you use . Some guys use a head to bolt up the header then weld it.good luck