Do you hear it knocking at idle? upon acceleration? Take a sparkplug wire off one at a time until you find it. COuld be a loose rocker arm, bent pushrod, bad rod bearing. My thoughts, rod bearing.
The plug trick will work with rod bearing failure.
You do NOT need a $75 an hour mechanic to troubleshoot that.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
