Hi, all
I am writing this for a friend, He has a 1991 GTA with 2.73-1
gears With no posi as well . he would like to upgrade to a 3.42 posi diff, the car currently has drum brakes what would be easier
getting a whole diff or swapping out the required parts? how many spline are the axles and are there any other things we need to know about before attempting this swap?? Thanks for all the input take care out there GTA.............

 

A 91 has 28 spline axles. If he wants to keep drums, the easiest/cheapest way would be to locate a used posi (an SLP takeout would be good, if they still have them...I heard they didn't), a new set of gears (or salvage yard if he feels lucky), and a bearing kit. For about the same price, he could get a disc 4th gen rear (94-up 6 speed cars use 3.42s) and swap it as a whole. It is slightly wider, though, so the wheels will stick out more (though not really enough to look bad).

 

Thank you! any one else ideas please ??? ttt GTA.......

 

yeah i would try and find another 10 bolt rear end from somewhere that has disk brakes that has 3.23's or 3.42's and then add a new posi unless it has one already in good shape.

thats what i would do, i like the 90 - 92 10 bolt rears.