Hello just installed 315/60r17 rear tires on my 01 Silverado (nitto nt555rii's). They are hooking really good! And I am happy with the fitment. The tire diameter is 31.9". I have 17x7 wheels for the front but have yet to buy tires as I don't know how wide and tall I should go. Should I be trying to get as close as possible to the rear height or should I get like a 30," tire?

 

I’m assuming 2wd? If so. That’s all on preference on what you like.
Me personally I love when people do that set up then do a bigger rim in the front and get some when close on the tire size.

Like this. Clearly stolen. Not mine