May use rear end gears from S10- or Monte-where can I decode the axle ratios?

I have a Haynes book that lets me know what the F body rear ends are by the numbers stamped on them. I am told the 80s S trucks and Monte Carlos have the same 10 bolt guts . Is there a site that has the decoding for these other rear ends? Are the other cars I should also be checking for? I need at least a 3.42 and hopefully posi.

not sure any sites,but u can count the # of teeth on the pinion and ring gear and divide the # of teeth on the pinion into the # of ring gear teeth to get the ratio.

not sure if thats what ur lookin for,but hope it helps

chiltons will tell you also. go down the the local book store and look them up so you dont have to buy the book :)