i have searched for literally hours and i am still lost...
i want to know just about everything there is to know about gearing and axles and sizes of gears and axles and what they are good for... just need someone to point me in the right direction.

for instance i have a 97 4runner and I want to upgrade to 33"s but i understand that i need to upgrade my gears as well. I have read that 4.88s is the right size gears. Also when looking into air lockers the site asks if i have a 7" or 8.875" something or another...

i would appreciate any help i can get...
thanks