I would take off the valve covers, pinch off the crankcase ventilation
hose coming off the breather tower (it will idle poorly other wise) and
start it up. Compare both sides to see what gets lubricated and what
doesn't. I suspect a blocked oil passage.
        Failing that I would remove the rocker assembly and verify open
passage ways(push rods and rockers) with a can of carb cleaner. Inspect
the shaft of the bad rocker for galling.

Good Luck and Drive Safely
Ken Lewis
86 Crewcab, 60 356 T-5
http://Neksiwel.20m.com/  My German vehicles,  O2 sensor help, headlight
relay mod
http://EB03.20m.com/     Everybus 2003 pictures

________________________________________________________________
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
Only $14.95/ month - visit www.juno.com to sign up today!