The Situation: 360 Water pump

Make your life easy, get brackets, pulleys, P/S, and water pump from a 70+ small block, of any displacement. Only hang up is the 273/318/340 timing covers wont work due to the end seal to pan U. 360s are larger, and the timing tab is on the drivers side. but with an aluminum water pump and matched brackets you should be ok. Check TDC with a piston stop to be sure. Good luck with whatever route you choose to take.