A V8 swap for a ranger is alot of work... and most of the aftermarket kits are for older ones with twin I-beams, but It fits well. First I would say take a look under the hood of a 96-01 explorer 5.0, that'll give you an idea of room. I'm not positive, but I think the SUV headers(or manifolds on 00-01) fit the truck. The steering box is an issue(even if its a Rack) and either a short filter(FL300) or an adapter is required. Explorer engines have good heads, and making the PCM and harness fit is a few weeks of work, but sometimes are hard to find. However if you plan on using a manual trans, the explorer PCM needs tricked, or reprogramed, and its sensitive to changes(headers, throttle body, and so on). Carburated systems are the cheap alternative, but mileage and reliability suffer. Holley makes several EFI systems that will work for you, but to the tune of $1200-2000!! Your driveshaft may need to be shortened or replaced with a stronger unit and if its a 7.5 rear, say farewell to that chunk of crap. Also lets not forget fuel, over 300-350 wont be supported by the stock pump. I;m not sure on HI flow for a ranger tank, so that may be an issue.
If you aint scared to rip you truck to pieces and have it down for a while, go for it. Just remember, everything you alter affects something else...
I may use a MarkVIII 4.6 DOHC motor in my 92, or a big block!! but then again I'm installing a turbo ready gt40 5.0 in an Aerostar!!
PM me if you'd like some more V8 swap tips.