I think you're headed in the right direction on all counts. M/T drag radials are a whole different ball of wax than the Hoosiers - I had 60 series MTs on my dart and got them working pretty well but had the most passes on hoosiers, which pretty much were a regular drag tire (I went to M/T because of sidewall rub). I can't imagine a 50 series MT tire is good at your power level and suspension setup because it'll be so much less flex.

Fuel system I think you have dialed in, but those issues are frustrating since you gotta just fix and wait till next time out