i need to replace the rubber grommit that is in the filler neck. i have a small gas leak right there so i am going to replace it. since i have to drop the tank anyways, i am going to install a 255 or 190lph fuel pump. i would like to have a stroker motor down the road or just a 306 with a blower. havent decided yet. but teh 255 will be teh better choice right? also, since we have return style fuel systems, even if i go with the 255 my mpg(dont really care, just want to know) should stay the same since it will return all unneccesary fuel back to the tank right? thanks, ryan