Which 19.5" tire to choose

Buzzcut1 wrote:
the axel on the SRW is the same as on the DRW you will be fine.

This is often repeated on here but is certainly not true for some trucks and may not be true for any trucks. GM for example uses 1/4" wall tubing for its SRW trucks and 1/2" wall for DRW, even though the center section is the same. Just because an axle uses the same ring and pinion section does not make it the same. Many SRW trucks do have 1/2" wall tubing though, even older ones, so it depends on the truck specifically.

OP: are you sure there are no 18 or 20 inch tires that will support the weight you're carrying? The reason I say this is that conventional light truck tires will have MUCH better traction on soft surfaces, both because they are wider and because they are softer. Truck tires are rated to carry their full weight capacity for the life of the tire, so you do not need a weight cushion. Even though 19.5" tires might have a tread that looks aggressive compared to steer type tires, I think you're going to be surprised at how little traction they offer with the stiff sidewalls and hard rubber compound. 19.5 tires are designed primarily for weight carrying and stability. Vehicles with 19.5" tires are primarily local delivery trucks like you'd see UPS and FedEx use, as well as tow trucks and similar. Outside of the military, medium duty trucks are seldom used off road, and the military uses very aggressive tires compared to what most pickup truck owners would use. If this compromise is necessary for the weight capacity, then obviously don't overload your tires, but you are going to be surprised at the lack of traction compared to light truck tires--that is why no light truck comes with 19.5" wheels and tires.