I found my old thread regarding the bolt angles and tapered washers:
search in titles for "D-66 questions" and go to post #34 for figures and pics. The correct tapered washer is 8 degrees. and can be used oriented with the thick side up or down to correct for early manifold on newer heads or newer manifold on old heads.
The angle for newer heads/manifolds is 10 degrees and it is 18 degrees for the 64-5 stuff
