I don't see how you can cut under the cab. according to the info I have found you need to remove 14" from the frame. I thought the problem was that there isn't enough room between the back of the cab and where the frame angles up. cutting under the cab you will have the same problem, the angled up piece will hit the cab before you get 14", and you will still need to re-locate the front bed mounts.
another option would be to move the front hanger forward and shorten the frame above and forward of the rear axle, that would keep all the shock mounts and the cross bracing in the correct place.
or Scott, you could (as Travis had mentioned) get the green one running then back half the crew and the white one to use the back half from the white one on the crew. That would give you the correct gas tank and all that jazz.
