Have some questions about a 5.7 swap into 73 Charger

I think you ought to give 03 Ramit's offer some serious thought. It sounds as though he has everything you need.

Joe Dokes
Not only do I have everything I can get just about anything he could need that's a factory part. Need a air box, want a fuse panel from a Toyota? Need a plug? Axle, or even a trans. I have access to alot for good prices. When it comes to ram stuff the deals I can get are hard to beat. Using tincup's numbers the harness and PCM would run 1700. And I'm selling allthat plus more for 800. I'll Gide the OP first dibs, but eventually it's going to go up for anyone who wants it.