Cool looking ranger. Looks like you are well on your way to "hooking" it up. My V8 s10 had one heck of a time grabbing anything, even at 50 MPH or so! They are tremendously light in the rear, but a nice suspension setup should do wonders. Boy, I want to get a big building built and build another one...something to do with my time!
I have had two 18 foot trailers, a Boot Heel (10,000 GVWR weighed 2240 empty) and my current heavy duty International (14,000 pound GVWR weighs 3200) so you are probably not far off at 1800 to 2000 lbs.
Having had 3.55 gears, I can tell you that these things seem anemic at best with those gears compared to the current 4.10's under mine. Unlike you, I pull with mine about 80% of the time, it sits in the yard until someone needs something HEAVY pulled!
As was said, it will do it and not moan about it at all, just won't do it fast. I pulled a load of firewood up to our clubs cabin once with the 3.55's on a steep hill, but a public road and thought I was going to have to shift to 4 WD low to make it. It just literally ran out of power. I can pull the same load, give or take a log or two, up the same hill now in second gear without the EGT's hardly moving.