so i recently swapped the aod in my 91 mustang for a c4. its a stock c4 but has a shift kit. the problem im having is the car doesn't seem to shift very hard under heavy throttle like it should with the shift kit and also it wont shift into 3rd gear until about 45mph. i have the vacuum modulator hooked up to the vacuum tree im not sure if that is part of the problem. im not sure if i try to adjust the modulator to get the 2-3 shift at a lower speed if that will cause the transmission to shift really soft which is the opposite of what i want. if anyone has run into a similar problem or knows about c4's all help is appreciated, thanks.