I have stock rear with 2,73 gears and i wan´t to change 3.08 gears in it. Do they change just llike that or is there something else that needs to be changed? I have open posi and would like to add limited slip posi in also. My mechanic says that he can change them if i buy the right parts for it. Is there a set that has all the parts ready? I´m not sure what gears fit in there and what kind of posi to make it work.

 

Setting up rear end gears is more of an art than a science. If the gears do not mesh properly you wind up with whining noise, fast wear, and even damage. One can follow the shop manual word for word and still wind up wit a poor install. An experienced installer has a feel for all the little tweaks and nudges to get things right.

 

Not much of a change going from a 2.73 to a 3.08. One size smaller tire on the back will give you the same results. You will need the posi. and the ring and pinion for the change along with the correct spline count on the axels.

 

Ok, i have to open it and make sure i get the right ones. I´m gonna order posi and new gears as soon as my budget allows it

 

I know this is an old post, but ...

The 2.73 gears are likely in a 2-series housing. (Versus a 3-series and a 4-series.)
In order to put a 3.08 in a 2-series housing, you will need a spacer plate. (Summit Racing sells them.) As stated already, you will need the 3.08 ring and pinion. Do you absolutely need a posi? No, but it's nice. If you do spring for a posi, get an Eaton posi unit. (Again, Summit Racing.) That's what came in these cars originally. Replace the axle bearings too.

While the unit is out, clean it and paint it.

 

I just installed a set up from Quick Performance. I had an open rear 8.2 a with a .256 gear and went to to a 3.55 . I went posi from Yukon with USA gears.They sell a complete kit for @$570.Great if you don't want break the bank and still have a fun upgrade.Setup isn't too bad if you have the right tools. I just installed it and its pretty good and impressive thus far.