Adam 
this is the engine with the new heads correct. then if the manifold vacuum is low that will cause the poor idle. where is the valve adjustment I asuume it was not preloaded when you installed the heads but the valves do pound into the seats and the valve clearance does change. thats where I would start 
Bob
  ----- Original Message ----- 
  From: Vanagon man 
  To: vanagon@GERRY.VANAGON.COM ; Robert Donalds 
  Sent: Saturday, June 01, 2002 8:38 PM
  Subject: Vacuum readings from my 88 good or bad; was digitool data

  Troubleshooting my problem...continued........

  vacuum is 9-10 inches of vacuum at idle.....when i add throttle it goes up to 15 in, then when i quickly cut back to idle momentarily goes to 25 then quickly holds 9-10 inches.......

  Any thoughts?

  Adam P

  81 Vanagon Westy (The Brick)
  70 Single Cab "Whitey" 
  74 Beetle "Ol Yeller"
  73 Transporter (STILL at paint shop)
  1988 Vanagon Wolfsburg 
  Used Vanagon Parts for sale (mostly aircooled)