Lloyd,
I have a 235 Chevy PU, with saddle type tool boxes that replace the fenders, like a utility truck with low boxes, (heavy not counting the truck itself), a 3.08 rear end, 295 50R 15 rubber. Your tires maybe taller than mine, but I can tell you that my small 235 pulls hills with no problem and a trailer just fine, not sure about a trailer and pulling a hill, small trailer OK. I do have a .73 OD, this pulling a trailer would not be advised until you reach higher RPMs, at least for my weaky. The 292 produces much more torque and should be no problem.
I will say that if it was my truck I would go to the 700-R4 OD tranny and keep my 3.73. This will give you better low end and ecomomy both city and freeway.
Have fun
Luis
