Hello, I have recently acquired a pair of rangers and was looking to do up the 4x4 for offroad (sloughs and prairie hills) and was wondering a few things

1985 2.8l 4x4
1.) will (30X9.5R15LT 29.7" height 9.8" width) these tires fit my stock suspension and body height
2.) if they fit, can i go larger and if so how much (more worried about width at this point)
3.) will i have to worry about excessive stress on my axles (if so what is the largest i should go)

additional info, i don't want to adjust torsion bars, i don't want to lift anything and i'm not worried about minor rubbing at full steering

 

Good read here on Rangers and tire size: Ford Ranger / Bronco II Tire Fitment


Width is more an issue with Rim/wheel choice.
The center line on a wheel is usually not in the center line of the tire.
Good read here on "back spacing" and what to look for in wide rims/wheels: The Ranger Station wheel guide - Everything you need to know!
You can use "spacers" to bring wheel out farther to avoid frame rubbing, but it is limited.

No, axles will not break because of tire size.
They break if you run 300 horse power, or more specifically higher torque, lol.
The torque required to turn a larger wheel/tire is higher but that just robs you of acceleration because the maximum torque your engine can generate hasn't changed, and your axle is rated to handle the maximum torque your engine can generate.
I am not an engineer, but that is my take on it.