1987 gmc square body with a semi theme

I have a 1987 gmc crew cab long box that I am giving new life. It started out as just a dump hauler that my parents owned, I fell in love with the truck as I got to drive it. Then came the issues. The motor in the truck is toast and if need to replace it So then came the grand scheme to build the ultimate truck. I bought a 12 valve Cummins as the donor motor. But I wanted a manual transmission. And I did not want the transmission that came with the dodge. So I bought a 13 speed eaton fuller to go into the truck Now this is were the semi theme is coming into play. Some problems I have had to over come are. Adapting the semi transmission to the motor. This took hours of machineing and lots of wd40 to adapt the motor to the transmission I had to build and fabracate custom parts to install the two components together