I got my transmission rebuilt they took out my J mod and put in their own shift kit no big deal to me if it works and they will warranty it this way. I also had a 3000 rpm 9 inch converter put in. I have not had the chip re flashed. The car is great till after about 2 hours of city driving when the fluid is way to hot the car will pop out of gear in first I cant tell if its the converter or the clutch pack. What do you transmission gurus think it is. The car does not have a cooler on it yet will be adding one soon I'm sure that will help keep the temps down but what is causing it to come out of gear when it is hot.