the driveshafts are the same length. there is one trick to that though because the ZF5 has larger universal joint bearings than the C6. not sure how the ZF5 size compares to the E4OD but it was nothing to change them over, 2 seconds and i was in business.
@LopezDR10 it wasnt bad. i was lucky enough to have just about every single part that i needed from a 5 speed truck that was getting parted out. once you get the old automatic stuff out (including the steering column), everything else is a direct swap. i didnt drill a single hole.
@incompletehunter i get about 13-15 mpg mixed city/highway, but i cannot speak to my fuel system's state of repair... from what i understand, underdriven you can get 18 mpg out of the 7.3 unladen. seems high to me.
One more thing, did you re-calibrate your speedometer, or just let it go? Also when you said you had to put in a different column, did you change out the whole thing, or just remove the column shifter and install the plastic cover in it's place?
