Another Set Back (very Frustrated)

So, are you saying that the motor was fine until the cam was installed? If so it would seem logical that the noise has something to do with cam install. Did you change lifters, springs, chain and gears? Could camlift be high enough that valve is hitting piston, retaining hitting valve perch, etc.? Is cam installed properly? Was crank banged around removing or replacing balancer? Is distributor in properly? I would go back and check everything done doing installation to find problem. JMO, Mike