Im looking for some new gears but not sure how big i can or should go. im sure i have the smallest rear end since i have an 07 st that is very basic...6 speed manual and 3.7. are the bigger gears a direct fit for the rear end? any info is appreciated.

 

ok so i guess i have the 3.55 gears. if i put the 3.92 gears in what kind of major advantages would i see? are they a direct fit?

 

im on rockauto.com and cant tell which part number are what size gears. any advice?

 

You need to find out what size gears you already have before you order new ones. Someone correct me if I'm wrong but with the 3.7 and a 6 speed you might already have 3.92. There should be a tag on the rear end telling what gear you have.

 

rock auto only shows an 8.25" rear axle for 05, wonder if thats a typo...i'm looking for 3.92 gears, but dont know what to buy, want to put a limited slip in as well...

 

according to the sticker from the truck it says i have 3.21 gears. so now that i know that....i still need to know what possible sizes i can use and which ones will give me the best results and what those results might be. are there actual size differences in some of the differential?

 

If you have the 8.25 rear then you can only go to a 3.55(iirc) gear anything beyond that you have to change the carrier. In the 9.25 you can put any gear ratio you want and dont have to change the carrier.

 

still having trouble finding the right part. it is the 8 1/4 diff. does anyone know a part number. would it even be worth it to go to the 3.55?

 

Try this site, http://completeoffroad.com/c-59860-g...sler-8-25.html

 

ive had good luck with yukon gear & axle.