I have a 528 hemi putting out over 700 hp. It runs on pump gas with radical cam 4 speed. I have the fitech 1200 hp on mine. A friend of mine has put several on before with little issues. Mine was a little harder to dial in because of it being so radical. But it is a different world as far as starting cold or warm. It learns your driving habits. As far as tech support they answered all my questions. I had no problem with them. Feel free to ask any questions.