starting up 340 that's been sitting for a few years

Electronic ignition is always a good call as a mod, unless you're talking about a high value car that is going for collector interests.

I still think I'd try and get it running with whatever it's got, though, before modifying anything, just in case you end up missing something in the wiring, you know it was something you did and not something time did.

That list, that 4spdragtop posted is a good route. I still think it's a bad pump or varnished lines. Ethanol is murder on factory type mechanical pumps if it sits. Confirming fuel will tell you.