I replaced the flexible fuel line and cleaned out the fuel pump (it's a single action, which has a built-in fuel screen). There were some chunks of something in the fuel pump--they were pebble-sized and kind of fell apart in your fingers. almost looked like cork gasket, or somethign of that sort. Anyway, I've taken it on several drives, including the same hilly highway, on hot (90+) days, and it hasn't hesitated at all, so it seems I might have cleared the problem up. I also got into the distributor, but couldn't find connectors at my autoparts store that were like the originals, so I ended up just wrapping the frayed part of the wire with electrical tape and putting it back together. Thanks for all the help, and if it starts acting up again I'll be back with more questions!