Great for Nitrous. Does NOT control fuel. Hemi fans old and new will be excited to see that the 6-Hemi Controller will connect to factory EFI fueled Hemis or will drive the coil packs of a carb retro-fit engine! It is designed to operate with both styled coil packs that are offered on the new engines. A wiring harness for each app is sold separately. Fits 03-08 5.7 - Will not fit 6.1L