The CV joint has a different bolt pattern than the u-joint because the CV joint is physically larger:

http://www.4crawler.com/4x4/ForSale/DriveshaftSpacer.shtml#Introduction

You can pull the front t-case flange off and put it on the rear output or you can redrill the rear flange. I used my front flange as a pattern for the holes in the rear flange and used a little jig to align the two for drilling:
[Linked Image]