Quote:

The tapered flange of the cast iron manifold for the original and reproduction manifolds seals with the bell mouth of the H-Pipe (no gaskets), unless someone ground the taper off your manifolds. Another key thing is the reproduction manifolds have to be dressed up as the flange area was not machined to remove the casting lines. If your manifolds were not "Modified" and still have the tapered flange you need to dress the taper to remove the casting lines.
Just some experience talking with repro parts, see casting line in picture, it leaked, of course.
My 2¢



Yes, this is the case. Looks like I will be breaking out the die grinder.
Thanks