Why advance timing?

Didn't end up doing much yesterday, but I got the speedo cable plugged in again. Seems the plastic connector is broken around the cable, so eventually I think I'll try putting a hose clamp around it.

Anyway, I drove it to work this morning (almost 25 miles @ 65mph) and I just had one tiny drop from the overflow hose. Seems to be better, but it's still fairly cool outside.

Regarding the suggestion that it could be the advance, I did check that a couple months ago. I had my timing light, pulled on the throttle, and saw that the timing jumped quite a bit - I don't recall where it ended up. Is that good enough? Should it be advancing to about 32* with the vacuum advance? Maybe it's intermittently having a problem, and so me manually advancing the timing to 6* w/o vacuum is compensating for it?