h: h: h: I didn't realize your fan was coming on at temp., I really did read your post I swear (well, skimmed). An old thermo could still click the fan on but take much longer than it should, but if it works at all that's enough to keep it from getting close to the red (as long as the rest is working correctly).

Your theory of the distributor being at fault seems more likely now, but still seems like the system should be able to cope. If the rad. doesn't have too many bent/clogged fins, I'd try water wetter like rebeld suggested.

edit: and you can get new ones on ebay (from what seems a reputable store), for 5th gens at least, for ~$40 including shipping.