I have to ask because it’s bothering me; is that bulkhead where the pump is mounted permanent? It looks like it’s bare wood. Once the bilge gets wet in there, that panel is going to be junk in a quick amount of time.

Just an observation.

yup,,that bare plywood needs to be encapsulated in resin and fiberglass.

It is bare plywood, but its not actually the bulkhead. For whatever reason it is screwed to the bulkhead, maybe for extra support? I poked around at the actual bulk head and it all seems solid
https://cimg5.ibsrv.net/gimg/www.off...d9dc88013c.jpg

Are those drywall screws holding it on????

Yep...
This project just got a whole lot bigger..
https://cimg6.ibsrv.net/gimg/www.off...927de85697.jpg

Ooffff!!

Working with pumps for the last 21yrs i can tell ya those are roller vane impeller type pumps so the only way you will cavitate it is if you have too small of a feed line from the tank to the pump or if the gas level is low enough that you suck air into the pump.... actually there is one more thing...the check valve at the tank fitting outlet. So i wouldn't really worry about placement of the pump. Obviously if the pump is mounted at the top of the engine then it has to work harder to pull the fuel up to itself but for basic installs on a boat i wouldn't worry about it being at the very top of a stringer or even slightly higher :)

What flywheel did you use?