Rough-idling 360, can't figure it out!

Not trying to be a dick, but, heave you considered a compression test,and teeing in a fuel pressure guage? also keep in mind there is a fuel pressure and volume test. Then there is vapor lock is the fuel line tight o the frame away from the exhaust? 1/2 inch makes all the difference as in 1/2 inch further away from the heat source.

Untill you do some real diagnoistics you are guessing, and throwing parts at it. Do you have a Chilton manual? the classic 64-71 book? it should have a tune up section in it. It will cost time but you wont be buying parts you dont need.