I pull a boat that weighs over 11K with a 92 F250 4x4 460/E4OD with 4.10's I swapped in from 3.55's. Truck is rated for 12K with that combo, does OK for nearly 300K on an untouched 460. On it's 3rd E4OD tho, and that's a MUCH heavier duty trans than a 700R4/4L60E. Have a 95 GMC and 96 Chevy both K1500's with 5.7/4L60E. No way would I use them regularly (if at all) for that kind of weight.