E-85 Carburetor help

Guys we recently put together a 602 on E-85 and we cannot get the calibration just right. I'm not looking for trade secrets by no means. Any typical suggestions would be helpful. 650 E-85 QFT carburetor and everything recommended as far as fuel line, Pump, Regulator, PSI...On restarts car has a substantial stumble...If we try to cure that then it gets lazy at the end of the straight and has a nice orange flame backfire lol. Just looking for some things guys might be doing as far as carb tuning, Plugs, Timing...Any help is appreciated PS: Buying a new JDR is on the list but them as long as all the other builders are really busy and 3-5 weeks out so I'm trying to salvage something with what I have while I wait for a new carb

first of all put the carburetor back the way it was when you purchased it---
it's always a good idea to check passages in a production built unit but you shouldn't need to start changing calibrations on it to have reasonable success
by checking passages ---I mean make sure everything is the same at least left to right and usually front to rear
I have found QFT carbs that have orifices behind the power valve that were not drilled

after you get your carb back to base line ---address the water temperature of the engine
a good running E85 crate needs to be at 200 degrees on water---if you are below 190 then that is the place to start
I can lay down several other things but we find water temp to be the biggest issue

let me know if you need more
Brad
www.race-1.com

Call blp or Braswell....they will help. Visit/join racingfuelsystems.com... Mike Laws and other pros are regulars.

Thank you Brad and Krooser.