i have a buddy with a yj with a 4.3 and a 700r4 on 60's front and rear running 39.5's. he ran a 21 spline tcase for a while, then downgraded to a 4spd atlas that blew up 3 times on him. now he has a 2 speed atlas while aa is working on redesigning the 4spd. every now and then he makes a comment on how he should of stuck with the toy tcase and doubled it up. I think the toy tcase will hold up fine. i'm putting my buddies toy case behind my buggy with a tbi 350 and 700r4 on 60/14 with 39'5's. for the tranny, i would go either 4l60e(or 4l65e if you know a good builder) or go with a 700r4. turbo 350's and 400's are great, but 1st gear isn't so low. just my
