For about 1 minute today I was having a strange loss and regaining of
power between 55 and 65mph. It felt like maybe the tranny was slipping in
and out of gear - although the slip back in was far too smooth and the
engine never rev'd - just stayed where it belonged on the tach as if I
were cruising.

I dropped to 55mph and it stopped happening, so I built up speed again and
no problems. Climbed a few large hills and some steep inclines on a 100mph
drive back to SF where I think had to climb big hills. No slippage and it
held at 75-80mph fine on the freeway.

I added gas and that was about it.

Doubt i have anything to worry about, could have been gusts of wind making
the Vanagon drive strange, wasn't necessarily mechanical. Just felt like I
lost power and regained it, lost, regained - but no changes on the tach or
abrupt reengaging of a trany.

Hmm?