If your going with the 12V it will be way easier. Less electrical! Whatever you do dont use the ford tranny (manual or auto) they wont hold up. I had a buddy do a swap, and went through 3 ZF tranny's before going to the nv4500. The cummins has way more tourque than any of the older ford tranny's can handle. Stay away from the GETRAG tranny as well. They dont have a removeable race for the rear output, its machined into the cast iron case. I am actually getting ready to do a swap with a 12v and nv4500 into an old 60' f500. got the motor and the tranny already just have to get started.