My Installation
I have a 1985 E35-3, so I don't know how similar our boats may be. I installed a Flojet pump which is, I think, a 3.5 gallon. It's very compact and easily fit inside the vanity in the head. It's plumbed to the sink drain/head raw water intake hose. I installed the Jabsco flush mount washdown outlet on the side deck right above the head vanity and ran the hose through the sliding cabinet behind the toilet. I keep the coiled hose in the anchor locker where it is handy for it's principal purpose. It was a neat and easy installation. I find the water pressure provided by this pump to be more than adequate.
Laura Bertran
Footloose, 1985 E35-3
Annapolis, MD