if you can find one that hasn't rusted away, it's kinda hard to beat a Ford Aerostar...
Dad was a Retail District Manager, over the years he had maybe 6 of them as company cars, used to haul merch between his stores...(drove around 60k mi/year for a while) even with the Vulcan 3.0, they never balked at being filled to the brim with all sorts of Stuff. Pretty consistently got around 20mpg even loaded down.
at one point, when his van was in the shop(electrical defect, the whole gauge cluster stopped working), he used his Personal Chevy 1500 to do a couple of transfers... It Didn't Fit as much stuff as his Aerostar.
IIRC, same driveline as a ranger, and if you are handy with a welder, and can fab our own motor mounts, I know for a Fact you can fit a 302 in the bay....