I've got a knock that is loudest at low rpm ('66 coupe, 302 2 valve). I've replaced the lifters, checked the tension on the rocker arms, and the rods are straight. My only conclusion is that the mechanical fuel pump is worn (the car has been sitting for four years). BUt before I go and start pulling parts I wanted to know if this is the right answer. Any opinions/suggestions are welcomed.

 

Is that where the noise is coming from? If it is, I would say that is is a good place to start. Its hard to say when I am not there.

 

That kind of vibration/sound/knock would be unusual from the fuel pump i think.

 

no it's possible...it could have the wrong F/P rod..and it's cheap to try so buy a new pump and a new rod from mr. gasket..also do you have power streering?

 

The knock is coming from the front of the engine, on top.

The car does not have power steering.

The knock sounds like a collapsed lifter, but I replaced them and it didn't remedy the noise.

 

Check your pushrods?