Updates... Some good, some expensive.
After reading the replies about the pumps, I decided to try one of the airtex pumps from Amazon, to see if it was actually a Racor, figuring worst-case I return it. It was not a Racor, even though the picture in the listing showed the Racor part number. It had no markings on it at all. I tried it out, and deadheaded it would build well over 100psi, pegging my gauge, but boy did it make noise. Even when I hooked it up in the truck, it made a terrible racket. Regulated pressure was in the low 60s, but I noticed that if I left the key off for a bit and let the pressure bleed down, then turned it back on, it would take several seconds to come back up to pressure. It would get there, but slowly. I did drive it, just for giggles, but it showed the same problems from before, only worse. Anyhoo, that part's getting marked "defective" and sent back.
Experiment #2 was to try a used HFCM from eBay. for $150 and a 90 day warranty, why not? At this point I didn't really care about time, I don't need the truck right now anyway. As soon as I unwrapped it, I knew it wasn't gonna be good. I could smell varnished fuel. I pulled it apart to at least take a look-see, and found large amounts of what I can only assume was dried up fuel, as well as some rust on the pump itself. It was obvious it had been sitting for a while. They said it came out of a running truck, but my question was "yeah, but how long ago?". I hooked power to it, and it just clicked like it was locked up. Whatever, they were super cool about the warranty, refunded my money and didn't even want the part back. So now I have a spare HFCM minus pump.
That brings us to yesterday. I ordered an OEM one from oemfordparts.com (~$300), but got an email this morning saying it's backordered. Got to looking around, and found one at AutoZone 25 miles away for $340. Done. I'm tired of messing with it. I put that in tonight, and did a deadhead test in the truck before I hooked it up. 100psi almost on the nose. Hooked everything up, regulated pressure is right around 60. Took it for a drive. Same thing. 😡 So I may have just spent $340 unnecessarily. I'm just comforting myself with the fact that it was only putting out 70 before, so it was probably on its way out. I did have a gelling issue a couple years ago that probably didn't do it any favors.
So now I'm looking at either an issue with the regulator, or a supply issue. I think I'll go get some long hoses tomorrow and try to rig up my can as a temporary fuel tank. If that fixes it, I'll be dropping the tank, otherwise, probably a new blue spring kit.