The stiff shifts you are experiencing are due to the internal clutches in the transmission engaging without slippage. When clutches are allowed to slip, you get the nice, smooth shift that most folks want in a vehicle. However, slipping means wear. A quick, firm shift creates much less slippage, meaning less wear, but you "feel" it (as you described, when accerlerating hard, you are pushed back into your seat).

Ask a transmission rebuild shop. They will explain it to you as well. Most folks do not want such a firm shift; they might spill their coffee or drop their cell phone while driving to work!

 

still nobody running the bullydog set up yet? like/dislike?

 

So I just bought the Evo New Evolution, airaid Throttle body spacer, Spectre Air intake, and a flowmaster catback exhaust. What type of power and performace am I looking to get out of my 5.4