My goal is to reach the 550/1200 mark with an automatic transmission(aftermarket, but not sure which one). I currently have a TST and aFe Stage 2 intake but am afraid to go past 3/3 on the TST due to the stock transmission and turbo. The truck does some medium duty towing and needs to be reliable so I would rather over-build everything than keep it on the ragged edge. Thanks for the input, all the information is greatly appreciated. Neil