Tonight I got ambitious and replaced the spark plugs on my plow truck. It's always stumbled a bit warming up, which isn't a big deal except for the soot it leaves on my garage wall. It turned out to be a well-spent nine dollars.
Most of the old plugs had too-large gaps, bent outer electrodes, and eroded center electrodes. None looked fouled or burnt, so that's a good sign. I would take a picture, but I'd have to fish them out of the trash in the garage.
After replacing the plugs, the truck fired right up and ran like a new, rusty, 23-year-old Chevy truck. It needs new spark plug wires, especially since I had to re-crimp one of the ends after I kinda pulled it off. Geez, I must have a good $15 or $20 into this truck already. I won't ever make that money back.