Okay I'm fairly new to this site and I love it! I have a 98 xcab that is a beast but its getting up there in miles. I plan on pulling the tranny and beefing it up a bit and I figured might as well do the engine while I'm at it. I was trying to figure out what I wanted to do as far as rebuilding the 5.7, buying a 5.3 and rebuilding it, or buying a 6.0 and rebuilding it. I know enough about all of them to do the rebuild/put it in but as far as power, fuel economy, and which performance parts I should buy I'm lost. I want it to have a little more huevos than what I have now, but still get decent mileage and have the potential to still be my DD. I'm planning on sticking around 2k into the engine in new parts and I just want to know which engine with which parts would be the best for my situation. I've heard that the 6.0 get like 20 to the gallon in the obs, is that true?? and i would like some input on what performance parts to beef up the 4l60e with. Thanks!!