Stopping the knock: Lower compression and ported heads...

Here is one. Its not a baby smoothe cam in a 440, but surely would be in a 493, right?

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=708&sb=2
One step up from that yet still streetable. I ran a Comp XE 285 once and it ran great without knock on almost 11.0 CR.

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=709&sb=2