I have a crysler 8.25 with 27 spline axles. If I got an aussie locker for a 29 spline axle can I just switch axles to 29 in stead of 27

 

You can't just swap the axle shafts. You would need to swap the carrier and the spider gears also and have it all set up properly. If you want a 29 spline 8.25, find one at the local junkyard and swap the entire assembly. Way less money and time involved. Then get the aussie and put it in.

 

You would have to replace the axles and the carrier, but the lunch box locker would replace the spider gears. You don't have any info in your profile, and you didn't say what size lift or tires you are running, but there are lockers that fit the 27 spline 8.25, and if you are running smaller tires 30-31s the 27 spline axle shafts will be fine most of the time.

 

Yeah well I don't have a lift yet but I'm getting a 4" with 33s. I'm waiting till I have enough money for everything.

 

I know this is old, but how do I know what spline I have? mine is a 98xj with the 8.25

 

You have the 29 spline. 96-01 all had the 29 8.25.