Tires: Different Tire Sizes & Original Recommended PSI, proper tire inflation, oe tire size

Question
The placard on the 4 door 2WD 1996 Ford Explorer says the OE was P235/75R15 that should be inflated to 26 PSI (front and back) and the wheels read 15" x 7" x 12".

Could 255/70R15 or P255/70R15 tires be used instead?  

If so, what would the proper tire inflation be for the (P)255/70R15 tires be for this vehicle given that the replacement tire size has a max PSI of 44 and the OE tire size has a max PSI of 35?

Lastly, is there any harm in using a G/T version of tire size (P)255/70R15 versus the H/T version of tire size (P)255/70R15?

Answer
Jess,

I hope you are aware the your Explorer was the vehicle involved in the huge tire recall some years ago.  The reason I mention it is - the placard should have been changed to read 30 psi, not 26 psi.

Using 30 psi as the original inflation pressure, a 255/70R15 would need 27 psi to carry the same load - and frankly, I think rounding it to 30 psi makes a great deal of sense.

But using a GT version with its enhanced grip is probably not the smartest of moves since tip over was one of the issues raised in the recall.