s10tahoe

How do I tell which gears I have in my rear end? And which gears will work best as a happy medium between acceleration and top end?

Okay guys so I took my 88 s10 tahoe for the first test drive yesterday after putting in a transmission and new front brakes and hub assemblies. And he did great other than the right calioer trying to lock up but i bought some new ones for it. My question is who knows what I can do to kind of...