> Could someone please explain what a resitor type plug is and which years
> of the Vanagons use them? I am currently using W77C's which are suppose
> to run cooler, but now am wondering if they were designed for waterboxers
> (mines an 82).
> 
Quite simply, resistor plugs are plugs that, literally, have a built 
in resistor intended to reduce electrical interference in radios and 
onboard electronics.  Plug wires may also be of the resistor type, 
there being several different formats.  Those fancy schmancy things 
us VW owners live with are solid core wires with a carbon resistor on 
that big brown plug boot (they unscrew if you want).  

Here's an interesting note on the three prong plugs.  If you are 
having trouble passing an emissions test (or are frustrating with a 
ratty idle) even with a brand new set of spark plugs in your 
machine-- put in a set of the 3-prongs.  It has made enough of a 
difference for people to pass emissions tests with no other changes.  
I greatly improved a rough idle in my 1.9l waterboxer by switching 
from regular plugs to those horribly expensive 3-prong.  I'm a 
believer.  I thought if I just kept a fresh (no more than 10K mi.) 
set of regulars in it would be as good if not better than the 
3-prong.  Nope.  (Your mileage may vary)