Pretty positive this is hung valves due to either the push rods not being
centered or too much adjustment of the valve adjustment screws (Bentley
Manual is WRONG when it says two turns should only be 2 half turns at the
most with fully pumped lifters.  When lifters aren't yet pumped up run the
engine with no preload on the valves until they pump up.)  A compression test
would confirm this very easily.

I bought a van that the heads were just replaced on and the PO couldn't get
it to run.  Bought it for a song.  30 mins later (after proper valve
adjustment) the motor was singing a sweet song and the PO was having labor
pains.  :)

Thanks,
Ken Wilford
http://www.vanagain.com
John 3:16
Phone: (856)-765-1583
Shop:   (856)-327-0027
Fax:     (856)-327-2242