Nitto Terra Grappler Tire pressure?
 

I have 315 75 16 terra grapplers on my 1500, what pressure should i run in these tires?

What did the tire dealership put in them? Use what is on your door sticker and adjust form there. It all depends on your driving and where you drive.

about 36-37.. does that seem about the right pressure?

Where do you drive it the most? On road or off road? What does the side of the tire say? What kind of truck and year model? That does seem like a good number for pressure though.
With my 20's (275/55/20 stock size) I run 34 in the front and 30 in the rear cold, but after driving and the tires are warm they register 36 and 32. Roughly 2 pounds of air pressure difference between hot and cold. I run my pressure this way, because it keeps the front from feeling loose with the side walls flexing and the rear sticks better in the turns. And by running a lower pressure in the rear it keeps the center from wearing out as quick between rotations.
Like I said, It all depends on your driving and where you drive and how it feels to you. If you off road a lot then a off roader would give you better input. I am 95% of the time on the freeway.

its usually on road, its a 2000 silverado 1500

the only thing on the tire says is 50 psi max

I think I would run 42 in the front and 40 in the rear and see how it handles from there. If it feels too stiff in the rear drop it down 2 more pounds. And iof it feels to stiff in the front drop it down 2 pounds. And vice versa till you are happy with it. Like I said itr all depends on how it feels to you.

put some chalk on the tires and drive forward adjust the pressure till you have the proper tire contact.

I do not follow what you mean by the chalk thing? I never heard of that method.

depending on the tire and rim combo can change your air proper air pressure to much air and the outer edges of the tire wont have much contact pressure to little air and the outer edges will have more pressure than the center. to find the right pressure for your rim/tire combo you can use chalk to see how your tires are contacting the road.

Okay I follow you. That is basically saying by adjusting the tire pressures for handling and I guess I should have mentioned tread wear too.