Someone asked me about the cost of the swap on another forum, so I've done a bit of a break down of 'how cheap you COULD do it, and what I'm looking to do'
It REALLY depends on 'how far you want to go'.
I think I'm going to do a compression test on the 5.0 while the explorer is still together, and decide what I feel like doing.
If I just re-gasket the engine while its out (so like rear main, oil pan, water neck, intake manifold, water pump, etc, etc, ~$150) and not pull the heads, and drop it into the Ranger, I can get away with this VERY cheaply.
Cost break down of a total bare bones swap:
I paid $300 for the 99 2wd Ranger I picked up.
I paid $675 for the 00 2wd Explorer I picked up (its a runner but rusty and leaking coolant from the water neck gasket).
IF my ranger was a 2wd "Edge" with the torsion bar front suspension, you can just use the Explorer engine mounts and brackets.
My truck being a coil-spring truck, I need to use a custom engine mount plate (~$100 to have made by a machine shop), and the 4.0 SOHC mounts (HAVE to be OEM Ford, cannot be aftermarket, which are about $40 a piece).
With my last truck, I was able to re-use the Ranger driveshaft with the Explorer slip yolk and a new U-joint (all of $10).
The 3.73 disk brake LSD 8.8 out of the explorer is worth $150-300 depending upon finding the right buyer, the interior and wheels could probably fetch me another $200-300 out of the explorer.
This could have me into this project with a running and driving V-8 ranger for as little as $500-600.....
HOWEVER, I plan on using the explorer interior and rear end, which then lowers the rear of the truck about 4 inches and gives me leather bucket interior with a center console in the ranger (which was also never offered). The DJM Spring kit to lower the front, and the front/rear shocks will set me back probably about $300-400 so I can have maintain a good ride-quality and have an excellent height without being overly low. My Orange truck had the same setup, and you can see in the pictures had what I'd consider an excellent ride height.
I'd like to toss a Cam and roller valve train into the motor (about $700 for the CompCam kit for this specific motor that will run on the Explorer ECU)
I will likely replace the front control arms (upper and lower), front brakes/rotors/bearings as to ensure the truck can deal with the extra strain I'm going to put on the front suspension with the motor and the 18X8.5 mustang wheels I already have laying around for it, which will be around the $300 mark for all that, and another $500 in tires.
If I can FIND a set of headers for it (Currently all aftermarket options are out of production), that will set me back probably $400-700.
I will need some custom exhaust work, but will make use of some of the piping from the explorer, I paid ~$400 last time to have header-back exhaust made to side dumps infront of the rear tire with a Cherry Bomb muffler for Parts and labor at a local 'cheap' exhaust shop. Since I'm going to try to make use of the Explorer Y-pipe I will likely be able to get away with a much lower cost on that, so I'll still budget about $200 to get something to work on the Ranger chassis.
That all being said, it will probably be around the $4000 mark when everything is said and done including the purchase price of the trucks and all the parts, but not everything has to be done all at once (I'll likely do the Mustang wheels and Tires in spring, and the suspension/rear end might wait until spring as well)
a more budget-minded person could do this swap for $2000 including the purchase price of both trucks fairly easily if they don't care about the bigger ticket power items (Cam kit/Headers/more aggressive tires/rims).
This whole thing can be done on a 4X4 truck for about the same money, but the X-fer case on the AWD explorers is a real-time unit and not a doubler/locker which adds complexity/cost/weight for those who want to do this for an off-road type truck.