I have an 85 vanagon and has about 145,000.  I purchased it about a month ago, so prior history is unknown.  I've been driving it around to see any problems it may have.  I do notice coolant smell, but am unsure exactly where it is coming from.  I don't see any apparent signs of leaking.  The engine seems good, appears to run fine, tranny seems good, no oil leaks, etc.  Today while driving I started blowing white smoke, by the time I pulled over to check it out it stopped.  Drove another 2 miles or so and started again and stopped.  I decide to go immediately home (about 4 miles). While driving home I went over a bridge and the smoke came rolling out excessively (James Bond smoke screen thick).  By the time I reached the top, the smoke had stopped and the rest of the drive home, there was no more smoke.  There seemed to be no apparent loss of power while driving.  After I got home, I checked the oil and the level was high.  It was a brownish/red color, no foaming.  

Does this sound like a head gasket?  Why did is smoke intermediately? 

Now, I'm thinking of rebuilding the engine.  I've rebuild a couple of type 4 air-cooled and this engine doesn't look too much different.  I'm debating of whether or not to do a complete rebuild or just do a top end rebuild.  Anyway thoughts and suggestions would be kindly appreciated. 

Thanks,

Mike