What spark plugs for 340

I bought 24 Autolite 65 platinum on sale plus a rebate. Made them around a dollar each. I normally buy copper plugs for a points ignition, but the price was the same. Supposedly platinums extend the heat range. I don't know if they do, but no complaints the car runs strong.
The more exotic metals do last longer. That's about the only benefit as far as I know.