Hi I have an 86 westy (with AC) with 79k on the original engine that appears to have had new heads at some point.  I've only owned this since May.  I've put 2000 miles on it so far with no real problems except one instance of overheating with boil over.  Normally the temp guage stays right at the led level in the middle with very little variance (maybe the width of one led up or down).  I noticed the temp creeping up one afternoon after trying to coach my wife on parking and taking turns in a parking lot but no overheating or anything bad.  In July I went to a festival in WV, the van did fine the whole way there.  The festival  was on the top of a mountain and driving in involved alot of waiting, driving forward 30 feet, waiting 10 minutes, and so on.  I was in line for about 30-40 minutes and then noticed my temp shoot up all of a sudden, I tried to rev up the engine and turn the heat on but things kept going up.  The coolant boiled over and I had to pull off an crack a beer.  I waited about 40 minutes, topped off the coolant and drove to my camp area.  The drive home was uneventful with steady temps and no coolant loss.  I just came back from a 400 mile trip with no temp problems.  Should I be concerned about this boilover episode or is probably a fluke as a result of sitting in traffic in poor conditions (hot dusty mountain road).  By the way my fan does kick on, not that often though, I rarely hear it when I park and turn the engine off.  Secondly what should I do if I notice the temp rising again, ie rev engine? shut it off?  I have more questions which I'll post in seperate emails.

Ryan