Ive looked on 3 different sites and im seeing different sizes.

01 ram 1500 2wd 3.9 liter reg cab. what size gears do i have? im thinking of changing them out for more low end power.

no idea....did you try a ram specific forum and searched??? that would be my best guess.................IF no one here knows DUH!

i guess i gotta get my vin # and have a dealer run it for me.