Which mark do I use to set the timing?  The one on the rear (larger) pulley or 
the one on the closer (smaller) pulley?

Also, I just replaced the head and gasket on one side of my engine, after 
getting it all back together, it idles rough, meaning the Rpm's are going up 
and down.  I remember my '84 doing this when it needed the O2 set (by VW, for 
the low price of $75) but it was not doing this before I replaced the head.  
Otherwise it runs great.  Is there some particular vacuum hose I should double 
check, etc.

Thanks,
Bryan

83.5 Westy (I like to think of that as the "Experimental Year" for w/c 
engines...)