How many rocker arm's are there on a 08 Hummer H3, 5cyl. Tried googling but no luck also was thinking of doing it myself but really not a mechanic, I believe ur suppose to set some type of pression on them..

 

If you do not know how many valves/rocker arms there are in a dual overhead cam multi-port 5 cylinder engine, I would stay far away from even attempting what you are thinking about. It ain't a swap out them arms kinda job. You will also need a specialized valve spring compression GM tool to allow the rocker arm and valve lash adjuster to be removed and re-installed. You have to follow specs for valve adjustment and torque requirements.

These motors are not like working on an old V8.

5 cylinders w/ 2 cams that each have 10 valves = 20 valve assemblies.
There are 20 rocker arms.