Its on the Camshaft...its a little arm with a spring on it on the back side of the camshaft..If you pull the side cover off the engine (its on the pulley end of the engine)..Then you can remove the camshaft and inspect the compression release..But dont lose the pushers for the valves because they will fall out of the block when the cam is released...

Make sure your valve lash is not too loose before any tear down.

oh ya good call on that...Check the valve gaps..How do you tighten them up though on the HH series engineS??Theirs no adjsuters??So you have to have the seats cut or new valves installed right???