ok i just rebuilt a vortec 355 for my nova and a few days ago when i was driving to school it started knocking all of a sudden. the oil pressure never got below 50 psi and it has brand new bearings in it. when i took the valve covers off the #7 and #8 exhaust rocker studs were broke so the valves werent opening. my question is do you think that would cause the engine to knock?

 

the exhaust valve not being able to open might have something to do with it. Do you have monster valve springs? What kind of cam? Need more info.

 

it has a lunati voodoo 262 219/227 .465/.489. the springs are z28 lt1 springs i think 100 somethin pounds closed 320 open.

 

is that a hydraulic flat tappet cam? Describe the knocking noise a "knock" could be just about anything.

 

well i wasent real bad at idle but it got loud once i gave it gas and the engine ran real rough. yes its a flat tappet cam.