1986 Chevy G20 3/4 ton, 6.2 Diesel

Considering that motor has maybe 120-130hp, and mid 200lbft of torque. It is speced equal to a 305v8 at the time. IIRC 3.42 gears are around 10K gcwr, do not remember if they went up 500 or 1000 lbs per GR. Either way, 4.10's might net you 11 or 12K lbs total.

The main goal of the 6.2, was to be a high MPG 305 v8. THe 6.5td was to be a cross between a 350 and 454 of that time frame.

Then if you have a 6 lug 2500, that is IIRC maybe 7200 gvwr max. You had to order a 3500 to get the 8lug 8600 gvwr setup.

If you are on a level, you might do ok. It takes about 105-115 hp to motovate 15K lbs at 60mph. That is about your limit frankly!

Marty

You are not going to be happy pulling with that engine. We're talking stuck in second much of the time doing 45 mph.
The one I had was updated with all new injectors and pump and even a rebuilt trans but still struggled just to pull itself down the road and with an 1800 lb camper and 2k trailer (with quads) it was at its extreme limit.

I had a 87 chevy van with the tow package, 3/4 ton. What I recall is that the MAX towing capacity of any combination was 6500lbs, most combinations were in the 5500lb range with the full towing package. IMHO your way over the limits for any towing even short distance.

The 350 I had, with 4.11 gears, 4spd overdrive and the full trailer towing package at the time was pretty much max'd out by 5500lbs. I pulled one trailer in the 4500lb range quite a while, and I could hold 50 on virtually any hill, and was in the 10mpg range. had a cargo trailer that was 5500lbs and it was 2nd gear on any incline and down to 35 on even a 5% grade. and mileage was in the 6mpg range.

The 6.2 diesel of that vintage was not turbocharged IIRC, and I think it's tow rating was the same or less than the gas. Personally I wouldn't even consider a 8,000lb trailer, tongue weight will be way over the van limit, second, the 700R4 tranny isn't going to like it at all. Even with the 3spd tranny, your still pushing the tranny over the limit.