Some converters will flash and pull the car higher with lower stall if the converter is around 5,400 to 6,500 i started out with 3,600 and now i stall at 4,600 and it went up the same and my converter is a 5,000 stall and it could be the torque of the engine some times will pull the car or more air in slick or put more air in the slicks could help and it could just be the track but you know your car better then any body good luck