1948 3100 1/2 ton, with 1956 235. Plugs look good. But recently started what feels like a mis-fire hesitation. At mid throttle. It idles fine, and will rev just fine while stopped. It doesn't feel like no gas. It feels more like ignition. Plugs look good. Points look ok. Cap and rotor replaced a year or two ago. I checked timing. The distributor doesn't lock down tight all the way. there's a little wiggle room. Any ideas what to check or replace next? It's bugging me. thanks.
