I can agree with the comment below. I had been having problems with my 74
  Thing, rough idling etc. and because I had recently put on a Jacob's
  ignition system and after finding an exhaust leak though I'd fixed
  everything. Driving home that night everything suddenly went to hell.
  Rough erratic running, etc.

  I spent weeks changing back one thing at a time thinking the Jacob's
  system had gone bad. Then trying other things. I didn't want to give up
  but finally got tired of no progress an took it to a shop I've had good
  luck with.  Turns out the left side dual carb had a slight leak at the
  manifold gasket (tip: I had tried to check for this myself by flooding
  the area with carb cleaner. The mechanic used slight sprays of starter
  fluid and listened carefully. While doing this it started to run a bit
  better. He said after one or two shots, the spray will soften the gasket
  and seal a minor leak, which will come back later.)

  On the right carb he found the base of the carb was warped and sucking
  air at the carb/manifold gasket.  Also a tiny bit of rubber from the gas
  hose had clogged the #2 main jet.  I hadn't checked for this because
  before this last round of problems I had had the carb on and off about 10
  times trying to correct plugged idle jetting.  I was SURE that carb was
  clean <grin>. I was reaching the point of being sick of looking at the
  car which finally got me to take it in.

  $150 bucks but it runs fine now and I can get on to that front end
  rebuild. Another nice thing is the shop has test equipment beyond what
  most home shops have.  He did a power balance test and I know that 3
  cylinders match, #2 has only 90% of the others.  He told me it may be
  simply the valves on that cylinder need readjusting, plan to check that
  also.  If they are adjusted fine I know to keep and eye on that cylinder.

  Jeff

  To:   vanagon @ lenti.med.umn.edu at Internet@ccMail
  cc:    (bcc: Jeff Lorentzen/TECH/KNOW)
  Subject:  Re: '74 rough running

  New Text Item:  Text Item

So Craig Standley says:

>
> Any advice is appreciated.  One thing I have gotten out of this is a ton

Sometimes, it's better to throw in the towel on certain things when
the amount of time invested is returning very little.  I took my '74
in to get the carbs adjusted and $90 later my van was happy, I was
happy and my wife was happy.  Not a bad investment for $90.  I had
previously spent many hours fiddling with the setup with no change
in performance.

So don't feel bad about chosing this option Craig.....