Hi Brad,
PRU is an '81 model like yours and has a side fill, cylindrical tank fitted in a square'ish box.
So much wasted space in there. Trouble is, its not all that usable due to being quite inaccessible.
But when the tank cover plate is removed, you can use some of the spaces.
https://www.mokeforum.com.au/index.php?topic=7631.msg160744#msg160744I didnt take any picks of the fabrication, but basically trial fitted the pump on some plate. Then drilled the 2 mounting holes for the pump in the cover, bolted it and tested that it did actually fit in there. Then I cut out enough to mount the pump and get the filter in.
Cut, drilled, and tapped a 5/16 unf thread into 4 bits of flat bar. Bolted them all up to the piece I cut out of the cover plate. Clamped it in and welded the tabs in place. Then it went for painting.
The pump is simply wired into to security circuit via the accessory curcuit. The pump only runs when the ignition is on.
Simples
On the Cooper S engines there is no hole in the block for a mechanical fuel pump, and given the mini fuel tanks were in the Boot, the fuel pump was often mounted to the rear sub frame and fuel was pumped all the way to the carbie from there.
For many years I had an electric fuel pump under the side pod cover over the tank level sender, but again, the ticking noise interfered with the ambiance of the A series engine idle at traffic lights