Chevrolet Repair: knocking, push rods, rocker arms

Question
will loose rods cause the lifters to make a knocking sound. I just had the heads off to replace a burned piston and put it back together and when started i have knocking. I also know that not all the push rods were seated tightly.

I also have smoke on driver side cylinders.

Answer
Loose push rods can rattle, but shouldn't knock.
Rocker arms that are adjusted to tightly, can push the valves too far open, allowing the piston to hit the valve, and that will knock.
Go through the proceedure to properly adjust the rocker arms before tearing it apart again.

Van