You really should install a spacer between the fan and pulley. I've seen metal fatigue/cracks as a result of not using one. It would help get your fan a bit closer to the radiator too which will also help with your cooling.
Yup, up to 1974 when they changed to the casting with the A.I.R. provision. The open chamber heads starting in 1968 will reduce the compression ratio a bit though. '66 and '67 920 castings were closed chamber.
If you're using the '64-6 LH exhaust manifold, using a later "smog" head would require extra clearance at the left rear (#7) exhaust port to keep from breaking the manifold. Best done by a thicker exhaust manifold gasket rather than grinding on the head. Best just to get the correct head.
Interesting. They don't list that number in the factory service manual, but, all my Formula S Barracudas have come with that radiator.....either with or without a factory shroud. I just happened to see the 75 code under your radiator heading on the broadcast sheet.
If you're going to use an A230 floor shift 3 speed, you'll probably want to use the '68-73 small block aluminum bell housing. That's probably the best setup for your '67. You could also use the A745 transmission and the '67-8 cast iron 3 speed bell housing too. Not quite as heavy duty as the...