Help! Hedders for a Duster W/1 7/8" tubes on S.B. With R/T heads??

Even when I used those headers on my old J heads they still had leaking issues. The tube is so big and the port sealing surface is small. You could weld the area in question on the headers and grind it flat. Or better yet get the headers for the W2 and the adapter flanges for the small bolt pattern stock type heads. That would cure your problem.