Chris,
"Input"....anytime it's cheap...lol. First I don't balance engines for a living... I'm just a tool and die maker...I went through the same things you are except I had a 6/1 and you have a twin internaly balanced...big difference but still in the same arena. I found even the guys that balance engines for a living don't know what the correct % for yours or mine should be, and there lies the problem. They know the best % for smallblocks, bigblocks, Harleys, and you know a guy that knows continentals, and such. I don't believe your engine will be 62% If I remember right it has aluminum pistons and turns a higher RPM. You need a guy that has delt with any engines with a slight resemblence to yours that has been through it and know the answer to a ballpark %. I was thinking maybe Wayne could hook you up with the guy in Tampa. That would be where I would be headed first. In the mean time as I mentioned I would start to add weight to my bobweight and see if it starts to improve the situation. The factory wasn't perfect but will get you in the ballpark of the correct % and tell you if it needs more on the bob weight. I have a cell phone with tons of rollover minutes I'll never use just e-mail your number and I'll try and really confuse you...lol!
Dave