Detonation. You are not using 87 octane fuel are ya?? Hemi's really need 89 octane.

 

I did accidentally put 87 in it. But it shouldn't do all that. I am pretty much getting a whole new top half of my engine but I just want it to fix it. Would a leaking or bad intake manifold cause it to misfire? I am guessing so. But would it also cause the valves to pit?

 

Oh and also, I spoke to the machine shop that did the heads and they said they found a broken spark plug with stripped out threads. So they replaced the insert that the plug goes in. I hope replacing the intake manifold will finally be rid of my engine problems.