Do you have an original V8 radiator for the car? If so, you would just need a 64-69 style water pump for the correct hose connections. As far as aftermarket radiators go, try to check out what Mopar vendors that advertise in magazines.
K.O. is correct, it frees up a bit of power by only locking up when needed. The picture of mine is for a non-AC car. The air conditioned cars used a thermostatically controlled spring on the clutch.
Changing to that water pump starts a whole chain of events in your car. You will need the newer style alternator brackets, pulleys and power steering pump and bracket if you keep the power steering. What dictated buying the new radiator with the incorrect inlet/outlet for your car?
Sorry, the car is all torn apart so no current shots. Cosgig, I had those made about 18 years ago. When I tore the car down, I sold a few parts including the headers. I've got a set of 1 3/4" to 1 7/8" step headers made for the car now.
I agree, transfer all the stuff from your 273 to the 360. The 360 should have the timing marks cast into the front cover and will be a little difficult to see but is do-able. I put all the 273 stuff on my 66 Barracuda and it worked out just fine.