Tires/min.load range for tire
What is min.load range for tires on 1995 gmc k1500 pickup
The way you've worded the question is a bit awkward, so allow me to start in a different spot.
On every vehicle sold in the US, there is a sticker – commonly called the vehicle tire placard - that lists the original tire size and the proper pressure for that size. The placard is usually located on a doorpost or in the glove box – but sometimes it is located in the trunk or on the fuel filler door.
BTW, it doesn't matter who makes the tire or what pressure is listed on the tire's sidewall, if the tire size is the same as the placard, then the pressure listed on placard is also appropriate.
One word of caution: Some trucks use tires with the letters "LT" in front of the tire size - and some trucks use tires with the letter "P" in front of the tire size - and some trucks use tires with the letter "C" after the tire size. I am not a fan of replacing "P"'s with "LT"'s - and can NOT do the reverse.
So what does the vehicle tire placard say? The books I have list lots of different versions of your truck - with different tire sizes and some are LT's and some are P's.
Also, while LT's come in "Load Ranges" (LR), P's only come in "Standard Load" (SL) and "Extra Load" (XL) - which are not Load Range's.
But the books I have say that if the original tire was a "P" it was inflated to 35 psi and was an SL, while the LT's are inflated to 45 psi and were LR C.
But if you are going to use a different tire size than what is listed on the vehicle tire placard, the answer changes and the pressure has to be recalculated. The calculation is not difficult, but it requires tire load tables which are not allowed to be published in the Internet because of copyright laws. However, I have a copy and would be glad to do the calculation, but the starting point is the vehicle placard: Tire size and inflation pressure. I will also need to know the new tire size.