I forgot something very important & that is the different pulley that will be needed (with the alum pump) to get the belt lined back up & the right depth pulley can be hard to find & yes it might be easier to get another radiator & keep your iron pump. I dont have an ans to your Q about 66-67 radiator interchange without redrilling holes.

live every 24 hour block of time like it's your last day on earth