Just swapped in a 5 speed trans and it's been running great(after I got it to start, thanks to RonD) until a few days ago, it started to cut out at high RPM, or so I thought, now, I can hardly accelerate at all without it cutting out and bucking wildly until I let off the gas, and now its so bad, I can hardly drive the truck around the block. I bout a new fuel filter but I can't find the one in the truck... The high pressure pump in the frame rail is working (to what PSI, I'm not sure) but I wasnt able to feel or hear either tank pump working.... Please help...?

 

1987 was transition year for fuel systems in Rangers and other Fords

The lift pump in the tank was hold over from Carburetor days, High Pressure pump was added for fuel injection.

If engine idles OK then both pumps are working

Fuel filter can look like the one pictured in this thread: Fuel filter??? - The Ranger Station Forums
Post #5

Cartridge type, cover unscrews..........BUT

This may be empty, just used as a reservoir, and there may also be an inline filter
Seen here: FuelPumpFilter88 Photo by subford | Photobucket

You're correct that the symptoms match low fuel flow, lack of power at high demand for fuel, so dirty filter or "sock" in the gas tank could be the problem.