I'll tell ya why Jim:

The bird is back to her "start great one day, won't start the next day" routine. Plenty of battery power, plenty of starter action, plenty of fuel at all times. But for some reason she has days where she won't "ignite". Its driven me nuts for the past 12 months.

Then about once every week or two she'll give me this explosive BANG POP that wakes the whole neighborhood up when I crank her up, accompanied by that infamous thick noxious cloud of air-fuel mixture bellowing out the carb and exhaust pipes! Sets off the smoke alarm in the garage! Then an hour later she'll start and run just fine, as if nothing unusual ever happened.

I figure the distro assembly has never been replaced since I've owned her (other than the ACCEL HEI Super Coil and Cap assembly), so why not replace what could be a 38-year-old part.