5.9 Magnum engine, what parts to keep?

You can save a little coin having bullet regrind your cam if your gonna go with a non stock spec cam.

are you using a serpentine setup? I found that it would be easier and cheaper to go with that and use a junkyard ford taurus electric fan instead of getting all the stuff for a v belt setup.

When I pulled my magnum I left one of the injector rails. I wish I would have gotten all of the fuel injection parts. Now I have to find a rail if I ever want to go FI.

I seriously doubt you want the kegger intake for a 75 dart sport. You could sell that, but strip everything off of it first.