O.k. i'll be the first to admit that i don't know too much about these mod motors, but i'm making an effort to learn. Can someone please explain to me what a Return fuel system does compared to the returnless? I know the old 5.0's had the "Return fuel system" and the 4.6 are "returnless". Can someone explain to me the pro's and con's of the "return" type fuel system. Why it's a good idea to have this type of system when slapping on a power adder to the 4.6's. Most importantly of all, if the "return" system sounds so much better, why did FORD switch over to returnless on the 4.6's? Thanks for the help.