Brian, here are a couple of pictures that show the orientation of the butterfly to the counter weight, that's the most critical issues. That’s where the pre-made shaft takes the lead, that is if they got the hole for the counter weight drilled in the right place. The slot is not terribly important as you can tighten or loosen the tension till you get the balance correct.
Just click the photo to enlarge it and the previous page has a few pixs also:
http://www.pbase.com/dennygraham/under_hood&page=4 Not to put anyone down, but I personally would run a heat riser, why would the engineers have included them for three quarters of a century if they weren't necessary? Of course that has a lot to do with just what sort of performance your expecting from your engine.
Denny Graham
Sandwich, IL
