we've been using junkyard rubicon rocktrac t\cases they already come with a 4:1 and beefed up parts we just have tom woods order us up some 1310 style yokes and seals for it and i think they do a little machining to them i can't remember and boom oh yeah they are also already the 23 spline short input aswell. If you go this route make sure to get the case out of the TJ rubicon as it has the speedo and the JK model doesn't, which isn't a big deal if you do get the JK model you'll just need to get the dakota digital GPS speedo controller which works AWESOME! So far i am very happy with how its worked i used it in lloyds and pa_jero is using one aswell(both using JK rubi cases).