It's been a minute and just finalized what I'd consider a worthwhile update:
The inline pump has been removed in favor of a custom in-tank setup.
I'd been kicking the idea around for some time but was reluctant to go drilling holes and cutting up my fuel pickup on account of wagon-specific replacement parts being pretty sparse. But after finding out Dantes sells repro's, I felt better about modifying the fuel pickup to work with an in-tank pump since worst-case, I could just buy a new one if I messed up.
What I did
• Used the OE pickup/sending unit as the foundation so that I could retain the fuel level sender function
• I used a Holley Sniper 340LPH pump and a Racetronix harness.
BLT1 Bulkhead Wiring Assembly, HD Tyco (BCWA-BLT1): Pump Bulkhead Wiring Systems
Holley Sniper 19-342 Holley Sniper E85 In-Tank Electric Fuel Pumps | Summit Racing
• The original lengths of the in-tank wire harness were too short I replaced them with longer runs. For that pass-through bolt — which is how Racetronix did their primary grounding due to amperage draw limitations of the connector — I sealed it by putting a generous amount JBWeld on the threads and on both sides of the hole before tightening down the nuts.
• Welded a -6AN bung to the outlet to easily adapt to 3/8" fuel line
• Made sure that the wires and heat shrink used in-tank were both fuel-compatible. Zipties should hold up since they're not seeing any movement or force on them.
Issues after installing the new pump
Despite initially doing research to make sure I wasn't going to create more problems for myself by going to a larger pump and concluding it would be OK, I was mistaken.
The internal regulator of the Snipers are nonadjustable and set at 59.5 psi, but with the new pump the fuel supply pressure jumped up to 75 psi. Since Holley makes a point to make sure return line pressure is zero, that was the first thing I checked. It was reading roughly 10 psi on the return side so I routed the return port on the sniper straight into a gas can & confirmed it now read zero psi — Supply pressure still didn't drop.
I consulted a couple of people with years more experience building fuel systems than do and they were both confident the regulator had gone bad & I was finding lots of Sniper-specific forum threads that paralleled this theor
SO, I replaced the regulator thinking that was the issue, once again bypassing into a bucket — still too high.
And then I find buried in a forum thread that the pre-set regulators inside the Snipers can't handle pump flow much greater than the 255LPH the kits ship with.
This was surprising to see since the replacement regulator part states "A 175 GPH 10 Micron filter and a regulator preset at 59.5 psi". 340LPH is roughly 90GPH so, not too sure why the bigger pump is causing pressure to spike? Maybe it's just incorrect information on the part description? Or maybe there is something else about the Sniper systems/or fuel systems and pump sizing I'm missing?
Regardless, I have gone to an adjustable regulator now & that resolved the high-pressure issue.
Closing Thoughts
Frankly, I wish I had gone to an in-tank setup sooner The original inline setup was horribly noisy and I'm not sure how I convinced myself for the better part of a year that it "isn't that loud". By the time I was at cruising speed or high speeds, that inline pump noise was pretty well blended into the road, wind, & engine/exhaust noise, but at low speed and idle it was louder than the exhaust
In-tank, pump noise levels are effectively non-existent. It is now possible to hold a conversation or listen to music at normal levels.
