DJ is correct. However, all winches are not created equal. Over my lifetime I've owned eight winches on different weight 4-bys. This short history may be illustrative:
1. 1966 FJ-40 factory PTO winch. It was rated at only 2200 pounds. I kept breaking shear pins until I drilled the shear pin hole to accept 1/4 inch drill rod which brought the rating up to maybe 10K pounds. Then it worked fine. It would not work if the engine was not running, as in underwater. It did have the 3 speeds of the trans and hi/low t. case gears to work with, which helped when you wanted a faster line speed.
2. Warn 6000 winch. Way under rated and pulled great, with a rather fast line speed.
3. Warn 8000 winch. I really think this was just an up rated 6K. Fast line speed. I used this one over 300 times. Eventually wore out the tiny bronze spur get that drove the bull gear. I also pulled the front bumper right off when using a snatch block in 4 feet of wet snow.
4. Warn 8274 winch. Hands down the best winch Warn ever produced. This one had hundreds of extractions when I was a hard core jeeper. THE fastest line speed in the industry. 150 feet of cable. Just a great winch. 125 pounds. The only woe is that it stood high and blocked some of the air getting past the radiator.
5. Warn 3000. It was portable (fore to aft) and could do the job with a snatch block if terribly slowly on a vehicle weighing less than 3500 pounds.
6. Warn 15000 winch. It's on my TC and has done the job for me over and over again. 150 pounds. 90 feet of 1/2 inch line. Not portable.
The cautionary tale is: If using it without the camper on, the truck must be dead maned. Otherwise, even with all wheels locked up, the wincher will just be dragged toward the winchee.
7. China freight 9000 pound winch #1. It bearing housing on one side broke on the first pull.
8. China freight 12000 pound winch #2. Fried after a few times. Very short duty cycle.
The thing to know is the higher the rating the slower the line speed.
Another thing is: Is your truck frame strong enough that a very high capacity winch will not pull it apart?
How about the winch carrier? I think some folks are living on the edge with flimsy carriers attached to the front or rear of the truck.