The Factory computers are actually pretty good. I have a 4.6 Stroker from Golen Engines in mine. I had to install 24lb injectors and thats it to run. I also added a ported throttle body to it just to make it breathe better, but I never had to do anything to my computer or have it tuned. Ive never had any issues with the stroker in the mountains or on trails.

^^^what he said, running the same setup