OK so Ive been looking at old posts trying to figure this out before i start.
Ive got a 97xj with a 5speed, 31s,and a d30hp front and a c8.25 rear.I dont know what spline axles.from what Ive read Ive got 307 gears and to get back around stock i need to go with 410s. what i need to know is do i have to change both carriers out to get 410s in,and if so what is best jy vehicle to look for them in?

 

check on randys ring and pinion im sure they could tell you,
and if you want to pull it from a jy then just find a jeep with the same axles as yours. if your lucky you can find 410 gears in a 4 cyl xj at the jy, just make sure you get the right ones for the front because the teeth are cut the opposite way on a high pinion d30. if you have a low pinion d30 pm me i have a set im trying to get rid of

 

thanks,ill check them out.

 

U divide the stock tire diameter into the new tire diameter and multiply that number times the stock gear ratio. That result is the new gear ratio u are looking for (or close to it) that will give the same/equivalent mechanical leverage as the factory stock tires and gear ratio.

 

OK so do i need to replace both the front and rear carriers to put in 410 gears if my stock gears are 307?

 

Just the front, 8.25 doesn't have a carrier break. D30 is 3.55 and down and 3.73 up.

 

OK so i only need a carrier for the front anyone know what the best donor vehicle would be?

 

You can get them new for 60 bucks unless you just really like searching junkyards for 4 banger XJs.