basic tire / wheel question

[p7387]

hello guys
sorry for this basic question which i am sure has been answered someplace

i need new tires, the truck has 235 75 15 all around (are these stock?)
the truck sits ok but i would like a more "beefed" stance without going too big.
at some point i would like to jack it up evenly all around no more than 1"-2"
however for the present time what is the largest tire i can put on a regular rim with a regular suspension, i probably would not want to go much bigger than the 235 75 15

as far as rims go what are standard dimensions? i also need a new spare and i am looking for a basic no nonsense gm 5 lug rim. i have been looking in junk yards but can not tell what the correct type of rim is. are there any particular stamps or markings?

thanks

[VileZambonie]

So you have a 2wd obviously. The largest tire would be 31x10.5x15 The factory wheels are 15x7

[78 Chevyrado]

Here's the "styled wheels"  OE on my '77.  the tire is 31x10.50 15.


Here's the truck rallys


Both of the wheels above were 15x8.

I had 32's on my 87 1/2 ton with light suspension and they scrubbed a bit when the suspension was compressed in a sharp turn, like every time I turned in my driveway..lol

[bigblue09]

if they are stock rims. i have 255/75/15 or 255/70/15. i cant remember exactly. but they are the widest tires you can put on 15x7s.

[ont_guy_38]

I have 255/70/15 on 15x8 rally rims that size fills the wheel wells

[bigblue09]

when i get new rims i want to get like 15x8 or 16x8. not sure yet but i know i want them wider.