I'm having trouble with one (at least) of my lifters on my '85 GL.  If
my van is parked for extended periods (say a week or so) the first start
up is ugly.  Bad tapping from one of the lifters (can't tell which
though, the noise seems to come from everywhere) and does not go away
for miles (10-15 miles).  The van is very low on power during this
period as I suppose the tapping cylinders are not firing.  Once the
tapping goes away (normally after I shut it off after driving 10-15
miles, and let it sit for an hour or so, upon restart it's fine)
everything seems fine, power etc.  Is this time for a new lifter?  How
can I be sure which one?  I only have this problem if the van sits for a
long time...if it sits only 2 or 3 days I never have a problem.

One other thing, I noticed when I last did the heads that upon adjusting
the valves most lifters had a springy free play feel upon compression so
that the rocker could be pushed slightly by hand to compressed the
lifter.  Two lifters (I don't remember which) had none of this springy
feel.  I was certain that the pushrods were properly seated so I cranked
the adjuster on them keeping valve spring pressure on the lifter and
took an hour beer break.  Upon returning and loosening the adjuster,
still no springy free play in the lifter.  When I adjusted these valves
I had to tighten just until contact for fear if I went the recommended
turns past contact I might actually hold the valve open and have a
piston smack it.  Is this potentially the cause of my problem now?  If
so, is there any sure fire way to bleed a lifter that refuses to bleed
down under valve spring pressure (preferably a method that doesn't
require disassembly)

Thanks
Mark