THE KNOCK !! shes out now what?

Pull the rod and or main caps and see what the bearings show. Any gouges, scoring, bluing or unusual shiny areas? Any hammering evident between the halves of the rod cap? Or between the main caps and the block?
You can check side clearances with a common feeler guage...and bearing cleances with inexpensive Plastiguage from any auto parts store. Somebody here have a service manual handy with the acceptable cleances?
Other things to consider...excessive fore and aft play of the cam, thrust clearance on the crankshaft, vavle/piston interference.
Piston slap (usually worse when cold) can anybody think of anything else to check on? Clogged oil passages to a main bearing?
Hope this gives you some possibilities.
Alan627b