Against his better judgement, last year a friend had a Dominator redone by Pro Systems, and similar experiences. The carb came back with a ton of work done to it, and might have still been ok at WOT, but he absolutely ruined the part throttle drivability. He couldn't go around the block anymore without the plugs getting fouled. Was a super common combo too, just an LS7 big block Chevy shortblock with a normal sized roller cam and single 4 intake.