Im freakin retarded and I just cant figure this out. I have a G52/54 tranny w/ forward shift crawlbox and a top shift rear case all 21 spline stuff as far as I know (I didnt build it and they PO didnt say different). I have found a tcase that is 23 spline with 4.7's in back case and a BL output for a pretty good deal. What would it take to remove my back case and put this one in its spot? I have read about changing the input gear and to 23 spline and changing the crawlbox out but I need to know for sure.....sorry for the stupid question but need help fast so i can wrap this up. Thanks!!!!!