Ive got a 85 xj 2.5 5spd. with a np 231 21 spline..and a donor 00 GC 4.0 ho injected i-6 auto...im going to need a ax-15 tranny and a np-231 23 spline...would it be cheaper just to rebuild my 2.5, bigger carb. headers, no cats, lockers, and a dana 44 with 4.56 gears, and maybe a 50 shot of Nitrous..and is their a kit to upgrade my 21 spline to a 23 spline on my old np-231 ?

 

The cheapest thing for the tcase is to get one from a JY. Or you can change inputs for $190

 

thanks for the input guys, im still in phase 1 of this project..but cant wait to start digging with them claws...