I just bought a Spicer 5 speed twin countershaft to swap for the 13 and have located a twin shaft brownie. Next thing is to get a Raydan tandem air-link rear suspension. When I get the suspension bolted up, I will know where to notch my fifth wheel slider plate and get it bolted down and then start doing some pluming and electrical work.
Rear suspension is being shipped at the end of this week. Then I'm bringing it to my shop to strip the frame from the cab back, paint it, plumb it and repair cracked crossmembers and then install the suspension and fifth wheel.
