The 155-12 tires, radial and belted as from the 70's small cars, and dont forget trailers, work well for me.
I remember that thread about using the Pickup tires as replacements for the 8-16's on the rear also.
Something to consider is the fact that not all brands are the same, Diameter or rolling circumfrence
Loaded, and at the same pressure.
Goodyear's 5-12 ag was smaller than stock, gave me Torque wind up on hard soil. Even with more air.
The 155-12's,studded and unstudded, no Wind-up,even on pavement and 4wd.
Bridgestone's 5-12 ag, the OEM tire, no Wind-up at anytime.
So if you go with the "auto-truck" tires, Mark your existing tires,and starting point on the ground.
Go exactly 1 revolution with the tires,properly inflated, then measure the distance traveled.
After mounting the replacement tires, do the same thing for them.
Adjusting the air pressures up or down will get you where you want the tires to be,if there not too
far off to start with. Then I mark the rim with the pressure I need.
Best of luck,hope you find this helpfull. Lloyd