im considering doing an axle swap on my 86 305 firebird that currently has 2.73s in it. i want a 3.42 posi axle if i can find it but i have a few questions

1. are stock posi units even worth having (i kno ill prolly have to rebuild it) but ive heard even new ones arent worth a ****

2. how much does a good axle of the nature usually cost in the yard with around 100,000 miles or so on it

3. is any of this worth doing? the car has an lg4 with basic mods on it and im just lookin for a little better 1/4 mile times, however the car is a daily driver so i dont want anything lower than 3.42s

 

If the stock unit is funtioning, stick with it until you have the money or it lets the smoke out.

They work admirably but at replacement time there are a lot better choices like getting an Auburn or Eaton posi setup.

3:23's are really common to find. In good shape with decent miles a 9 bolt or 10 bolt should fetch $300 or so if it includes all brakes and lines. $150-200 for stripped down ones in functioning shape.

3:23 10 bolts or 3:27 9 bolts are the easiest to fiund for performance, lots more common than the 3:42 or 3:45 ratios.

Cheaper at yards obviously.

Going with gears is a step in the right direction as anything over a 2 series will make a difference.

You about 2 hrs out from chicago area, hit the nw in/chicago board here under regionals. We even have a few guys who do nothing but part thirdgen.

later
Jeremy