What compromises are these that you speak of ole wise one..
aftermarket suspension geometry must be adjusted so you can actually provide the ability to bolt it to an existing frame and keep a certain track width. usually there is a frame member in the way, or you have to "adjust" the design to fit. this may or may not provide proper geometry. now, if you get lucky and are pulling a donor suspension that was designed to be bolted in to a truck frame of same height, width, length, frame angles, etc. and it matches up to your frame.... the compromises have been minimized.
