You need to lengthen you drive shaft about 10 inches... after you do your framework, you have to measure for exact length.
Here are some more pics of the frame. That fish plate is where the two frame sections meet.
I used the rear cab mount as my reference, so the measurements were exact.
Then I had to cut and welt the rear mount higher on the frame.
Here you see how far forward the seam is from the rear mount.