My friend apparently thinks that he can take out his 4L60E and bolt and plug in a 4L80E in its place. I know there is a lot involved, just not sure how much. I need to know if the t-case will have to be changed, move or fab up new crossmembers, lengthen both driveshafts, splice in new wiring harness, torque converter?, cooler lines, shift linkage/cable?. So if anyone has done the swap or can tell me a little about it, your advice would be greatly appreciated. (it's a 2004 4X4 Silverado SCLB 5.3L)