So I mentioned that i had converted an internal Walbro 255 to an external and added it inline in the engine bay. The longer version of the story was that I replaced it with a cheap Rockauto pump based on nasty noises it was making. The noises turned out to be a symptom of a fluctuating level of pump strainer blockage coming from sediment in the tank.
After I corrected that issue I began to suspect that this used Walbro was perfectly fine and could be used again. I installed external inline pumps on the last two TMs i fixed up (Lancer and Spirit) after learning many years ago from Ondonti about how inline pumps suffer much less loss of volume/flow at high fuel pressures even compared to large/powerful single pumps like a Bosch 044. I wanted to install an inline pump on the van but didn't want to spring for anything if i could make this Walbro work. I had installed a used Walbro 255 external on my Lancer Shelby and the only differences i noted were a different case crimped over the pump body with suitable inlet/outlet fittings tapped into it. I suspected i could adapt the internal to work as an external if i could do two things: 1. Adapt a 5/16 hose barb to the rather large opening on the suction side, and 2. Defeat the ~75psi bypass/relief valve that the internal-style Walbros have (Ondonti tipped me off to this as well).
I had recently bought a 1/2 NPT tap to tap Acannell's 4th cylinder cooling plate for a 5/8" hose barb for this engine, and i noticed that the plastic 'inlet nipple' on the Walbro could be tapped for a 1/2" NPT fitting. I took a 1/2" NPT plug, tapped it for a 1/8" NPT fitting with a 5/16" hose barb, and screwed it into the pump inlet. I suppose it's odd that i happened to have these necessary pieces, but it worked out well.
For the relief valve, I had heard that some people simply smash the valve (a ball bearing) down into it's seat and then epoxy over it. I engaged my junk scavenging skills again and found some odd little screws that formed a very tight seal with the opening for the relief valve. I smacked the ball down into its seat and screwed the screw in on top of it to hold it shut. I have seen no evidence of leakage at either end of my halfassed inline pump with fuel pressures up to 75psi so far.
Unfortunately I didn't take pictures of the inlet end, but I can get them and edit them back into this post. Here's a pic of the Bypass Defeat Screw, though.
As for wiring, this pump is 'mounted' to the passenger strut tower, with power coming from the the coil positive terminal and ground being a ring terminal under a screw on the firewall.