I have that setup, too. I ground mine with a angle die grinder with a 3" 80 grit sanding disk.
I also did away with the factory clamps, I couln't get them to work well with the manifolds. What I did was install studs in place of the bolts, and put bolts in place of the dowells at the ends. Then I made new clamps from 1/4" stainless bar stock. I have no leakage problems at the head. By the way, my Offy came from Patrick's, it's not welded, but so far there's no leaks at the plugs.
Semi-related topic-have any of you had problems with the head pipe flange leaking? Iv'e tried several types of exhaust gaskets, but they blow out after about 3 months. Any ideas?
