Got a smoking deal on this 16.5ti Warn couple years back. Most folks probably don't like a rear mounted winch, but I have a few reasons.
1. Own about 1000ac of timber in Canada surrounded by Forest Service/Crown land. I am far more likely to be winching trees out of the woods, or recovering somebody else's truck, than I am to be recovering my own truck.
2. If I get stuck out back, most likely in the winter, last thing I want is to pull myself farther in. Winch back out, chain up, then proceed. If I get stuck with chains, then I am walking back to the house to get the Cat. Pull the truck out with the dozer, then fix the problem.
3. If you put your truck in the ditch, traveling, on the snowpacked ice, ( I've done it ), then that front winch is buried, and there is likely no place to winch to anyhow. Farther off the road is not the answer. Back up on the road, better.
I wanted something a bit lighter than the mounting plates I've seen, usually bent from 5/16 plate. They rely on the strength of the bend of the plate and a small brace on each side.Cantilevers the winch off of the bottom two bolts. Four bolts hold it to the vehicle frame.
I indexed the winch 90 degrees, then fully boxed the winch with 3/16 plate doubled over angle iron frame. This grabs all eight bolts of the winch frame and keeps some of the weather off of the winch. The box mounts to the 10k frame hitch with 6 - 7/16 grade 8 bolts. Missing from the pictures is a 3/8 bar stock brace that ties the back of the winch box to the frame, but that is the basic setup. Dual battery setup relocated to the center of the frame, runs the winch and compressors. Modified rear bumper in the future.


Two bolts on the back will tie to frame brace. May want to weld to box, bolt to frame. We'll see.

Room for another bolt, will put it in.

How it will sit above the hitch. 9.5 inches tall, just clears the tailgate.

 

Nice setup. I agree with your logic....

 

285 75-18s do not fit between the frame rails. I run a 5 wheel rotation, full size spare, and need that spare back underneath for bed room. Pulling it up tight to the frame left it flopping, so i built these two spacers from V10 head bolts and polyurethane tie rod boots. Think I'll notch the frame this fall, get the spare back farther up, need the ground clearance. Spare also butts up tight to back of winch case. Built/bent some 8x6 gussets I'll weld in to stiffen factory tow hitch frame.

This is how it ended up. I welded angle iron to the back of that 3/8 bar stock to stiffen it. Front angle will get scribed/trimmed in place, just there carry the bumper. Bar stock bolts tight to frame each side. Looking at building a spring shackle flip and some frame extensions for recovery pick points. If this all works out, frame, wiring for winch, inverter and trailer, and everything else will clean up nicely when we lift the box again.

 

Not using the level per se, just a convenient straightedge. Set the drop off the frame and then straightedge across.

Blue wrench the bumper in half, then hang the sections and scribe around the winch cage.

This is the basic setup.