[chevy72blu]

take off the valve covers and put a turn or two on the rockers that feel loose. Im sure using a torque wrench is a better way to do it, but doing it by feel has always worked for me. Make sure not to tighten em down too much.

You sure it isnt an exhaust leak? One time I thought I had a lifter clicking, and it was just a header gasket leaking a strange way.