well, its been doing this since i bought it and i cant figure it out!

drive around town normal throttle, truck runs like a rape date.

full throttle, the truck starts buckin and fartin around 30, then stops, and does it again at 50.

no black smoke, and the rpms arent moving.

tranny or engine?

 

Check to make sure your lift pump is running. Mine did the same and it was my lift pump. my IP was sucking the filter dry.