I eventually plan on pulling the LO3 out of my bird and am going with a carbed 400. I've got to swap the gas tank regardless, so while I'm down there, I'd rather do what I've gotta do. I know TBI is high pressure but not as high as TPI. Does anyone know if you can use a FPR and retain the same pump? Also, is this a return system and what would I do about that if it is? Thanks.