factory specs?

where can i find factory specs for my 2000 silverado 2500 6.0l?
i want to know my transmission and rear end gears. i know the perfomance specs (300hp & 355lb-ft) but would like more info.
does anybody know the formula to calcuate gear ratio? i have been digging through back issues of car craft and PHR with no success.
if you know the formula.... 75mph @ 2500rpm 265/75/16

HEY I HAVE A PRESENT FOR YOU....U WANTED GEAR RATIO WELL HERE IS A SITE THAT HAS EVERYTHING CHECK IT OUT....http://www.smokemup.com/auto_math/index.php
HOPE IT HELPS YOU OUT

SORRY THAT SITE YOU HAVE TO REGISTER FOR...HERE IS ANOTHER ONE THAT HAS SOME EQUATIONS...http://www.afamusa.com/formulas.html

thanks for the helpful sites. now if i can just find the diameter of a 265/75 tire lol
GOT IT! 3.13S IN MINE. ONCE AGAIN THANKS FOR THE USEFUL SITE