I made a mistake with Porsche 911 and learned the hard way
Long-distance road trips in a classic require a different mindset than road trips in a modern car. The car will communicate problems before they become failures — if you're listening. Unusual sounds, smells, vibrations through the steering wheel or seat: pay attention.
Carry a basic toolkit and spare parts. For a classic American V8: spare belts, spare fuel pump, a points set if it's pre-electronic, a condenser, a spare coil, a length of fuel line and hose clamps. For a British car: carry the number of a good flatbed service.
The joy of it isn't despite the engagement required. It's because of it. Arriving somewhere in a car you understand completely, having driven it attentively and brought it home safely, is a different thing than arriving in a car that drove itself.