Since I've been working around ignition systems the last couple of days, I remembered an old PMI trick. It comes from the days of Ford 300CID inline 6 engines which for reasons I don't understand, failed ignition wires somewhat more often than most engines. Wait for a moonless night, or open the garage door to let the exhaust out and keep the coach nose first in the garage. when it's good and dark, turn off all the lights. You want as close to total darkness as you can get. Pop the hatch off and crank the engine. Look all around the distributor and along the sparkplug wires. They should be completely dark. An eerie purplish/blue glow (properly called corona) indicates failing insulation on the wires, replace them.
My 23' has new Patterson wires, and the 26' has the ones that came with the MSD 'Flamethrower' setup the PO put on, neither show signs of deterioration. The ratrod toad looked like Yoda and Darth Maul swinging light sabers at each other so I invested 30 scoots in some decent new wires for it. Save yourself some grief before you drive into a rainstorm.

--johnny