What will I need to put my /6 in a truck

You'd need some serious conversion parts to keep those items. If it's just a putt around truck, you could put the whole drivetrain in it from the Dart but you'd still have to make a custom driveshaft for it and get the truck only slant 6 motor mounts, accelerator cable, oil pan, and pickup. If you plan to haul anything, you'll want to get the slant 6 version of a 727. Doing that will also let you use your existing driveshaft. You'll also have to do some cooling and electrical mods.