Vic two questions:
How do you make it pass thru - pull the rod?
Why not use electric as prime or backup and mech as primary?
I'll answer you last question first; the way Ford set up the OEM fuel pumps (
on top of the intake manifold) if the diaphragm ruptures, and you have an electric fuel pump hooked up to feed through the mechanical pump, you'll be pumping gas into the crankcase... that's not good!
Here's how I convert the OEM fuel pumps to 'pass through' pumps. First, I gut the pump, removing all moving parts. I use (
for lack of a better term) sliding closet door thumb pulls, you can find them at Home Depot, Lowe's, etc. The larger diameter ones are a very good fit when placed into the top portion of the fuel pump (you
may have to grind off the lip for a tight fit). This creates a reservoir for gas. I use JB Weld to fill in the gap. After the JB Weld is dry, I reassemble the top and bottom sections of the pump, using the diaphragm to separate the two sections (
just as the original pump did) this gives the outward appearance of an OEM pump, when it is installed. As a side note, I leave the push rod in the block and, I always carry a 'known to be good' mechanical fuel pump in the vehicle, just in case there is a problem with the electric pump. I had talked about doing the fuel pump conversion with Marv, here on the FordBarn, and he actually did the first conversion for me. It is easy to do and it maintains the OEM look under the hood, if that's important to you. One more thing, when using an electric fuel pump as the primary (or only) pump, you should always install a 'kill switch' to shut off the flow of gas if it becomes necessary. Hope this helps and was not too long winded.