1/2 tons suck.
BTW, is this a short bed, standard cab, long bed,....?
I towed a lot with my '75 3/4 ton Dodge, no problems (even with 35's).
I towed a 6500lb trailer from Logan to Moab and back once with a std. cab short bed 1/2 ton, I'll never do it again. There was no problem with power, even with the 33" tires, but the light truck weight, soft springs, and very short wheel base just sucked. Even with the equalizer hitch, the control was nervous, and I had to always keep the speeds extra slow. If the electric brake controller had failed, I might not have been able to even stop.
I replaced the half ton with a 3/4 ton Cummins, and I've never been happier. Even ignoring the extra power I now have, the ride and handling control (including stopping) actually makes the towing trips enjoyable.