Which timing chain cover and water pump set up are you going to use???
If you use the old 60's style cast iron oil pump and timing chain, then you need the older style pulleys...
If you use the aluminum water pump, then you need to run the newer style alternator mounting brackets and also the newer radiator...
But if your car has factory power steering, the 60's style power steering brackets for the 69 cars mounted off the hole in the water pump housing... so you would need to use the old cast iron water pump housing for it to mount properly. That would also require the proper old 69 and earlier radiator for everything to match up correctly...
Then if you are going to run A/C or not determines how many groove pulley for the alternator and water pumps....