When you get those new plug wires, be sure to get copper core wires, not resistance wires. It will make a world of difference. Also, I would get new plugs while I was at it, and go with Autolite 295 instead of the normal 303. This is a hotter plug and will be a lot more resistant to fouling under light use. If you're going to use it hard, stick with the 303 plugs.
After that, timing would be my next guess, even if it ran yesterday. I hope this didn't happen, but it could have bad timing gears and be firing at the wrong time.