I didn't have issues with mine (Xmetal). At first, there may be some high idle or sticking idle return but a couple of hundred miles will finish seating the throttle blades so that there aren't any idle issues. It's extremely important to follow the directions to the letter, especially the part about centering the throttle blade with paper. I don't know what your expectations are for throttle bodies but it's not going to add much - 10 hp is very hard to feel. Throttle response is the main thing.