Well, after your last post, and referring to the one above, and ron's comments, and the fact that a werks team driver is running a jp4, I had accept the possibility that I still might be missing something and decided to give it another go. Your last post indicated that I should lean the top and fatten the bottom potentially, and this one you suggested it might be the other way 'round. The important part being needle imbalance, something I've warned others about myself, and was honestly sure I had certainly ruled it out.

Welp, you guys were right. Re-tuned, top end ended up being 3/4 turn richer, bottom was about 3/4 - a whole turn leaner, and the idle stop got dropped a lot. The unavoidable high idle is gone, the temps are lower, and the motor feels noticeably better, especially on the low end and transition to full throttle -- I don't have to babysit the throttle to keep it from loading up as much. The best part is that I can knock out both the high and low speed needle setting pretty darn close just on the box by ear -- and neither are more than an hour off after hitting the ground.