The stock harness will work if you want a 10' anaconda coiled on your inner fender. Best to remove the PDC(relay box) and clean it up. The Ram will not have SKiM, only cummins and v10 with very rare exceptions.
It will run much better with a 5.2 AT PCM from a Ram or Dak anyway. Cheaper than a flash to get it on the road.
If you had a 904, the drive shaft should be the same spline, at least a few I have tried have worked. Stock mounts can be modified with spacers etc or Schumacher.
player1up is right on the linkage, you will have to use TV cable or it wont shift.
Dont waste time installing factory pump in tank, I did it before they made FI tanks that bolt right in, nightmare pita . We use Tanks Inc tanks with GPA 4 pumps and have complete an line kits to the magnum fuel rail.
Do yourself a favor and swap out the cam before you put it in, the factory 5.9 turd stick leaves way to much on the table...think 245 HP to 350HP....drop in cam, valve springs and timing set.
PM me if you want a FABO discount on anything....our site has many helpful FAQ's on Magnum swaps as does magnumswap.com. If you have any questions, I have over 75 magnum swaps and 300 harnesses out there running great.
This is what a harness looks like without PDC, PCM goes inside with relays and fuse panel. super clean install.