Looking to learn about rear ends!

[Heavy87Chevy]

Hey guys,

I'm sure like alot of you guys I spend alot of time thinking about my truck, but it was winter when I bought it & up where I am that meant I didn't get much of a chance to thoroughly check it out, & I've learned so much more since I've last laid my eyes on her.. Right now its sitting at a transmission guys place about to be fixed up, theres something wrong inside the transmission & that is beyond my current knowledge so now I wait..

What I'm wanting to learn/discuss is this: how do I figure out what the gears are in my rear end? I've got an '87 Chev V10 LWB 4X4 with a 92 corvette tpi 355. The rear end is 10 bolt I believe (does that mean its posi!??), & when I looked on Chucks Chevy Truck Pages, everything is leading me to believe that I would have 3.08:1 ratio.. I'm running 33" tires & I'm considering going to 35" tires & I'm wondering if my rear end could handle 35s, so I'm also wondering, how do I know what rear end is best for specific tire sizes. I'm willing to swap axles & everything, over time, to get the most out of my baby

Thanks for any help, I'm really just a youngan getting into squares & I have much much more to learn, but heres a pic of mine .. I'll post more pics when I get back from vacation in a week!