It has been a while since i have been on here but i have a problem with my mustang and hope you guys can help. I have a 96 gt and i just put a pi motor in it. I put longtubes on it cai, bbk tb, everything dropped right in and fired right up. The problem i am having is at about 3k uder a load you can feel the power almost flat line. It sounds like it is loading up or something. The car drives fine but under a load it feels like there is no power. The only thing i have done is change the fuel filter. The car has not been tuned but i figured it would run better than it does without a tune. Can someone please help this is driving me nuts.