To elaborate on what Rod said ,E & F pumps are what we call "insert jets' they built/designed "set back" mostly out side the boat , the parts are for the most part interchangable with the exception of the main body/suction piece . A swap would be alot of work like he said ,the E's can actually be made to work quite respectably with a few simple mods , I know of folks with moderate HP running very respectable numbers with E's . Josh is "cookin up" some stuff as we speak ,as one of his boats is an RE test bed ,I'm sure he'll chime in later Tom
just a note with E pumps "flying the boat" can be seriously detrimental to the suction housing ,due to "shock loading"