Lots of good times with "Goldy", he actually let me drive one of his Pantera's on an LA Freeway, really impressive, the stuff dreams are made of - LoL !
I'm not sure about the CS & KS, but those could be factory stampings as TRACO requested special handling of the block and head castings, mainly just to make sure that they were cast properly to the print specs; e,g: Material, tempering, centering of the mold core pieces, etc. The factory must have had some way of keeping track. they were helpful in selecting castings for us. As with all production castings, core movement or placement is (was then) dependent upon the workers and how the mold was handled, there's always variations, we just ask for minimal variation from the design prints.
TRACO did not actually stamp the earlier blocks, later on we used a code stamp on the top front of the block, there is a small land on the block cylinder surface in front of the # 1 cylinder. The code contained a date and the engine CID as I remember.
Each main bearing cap is stamped with it's position number, as are all components in the assembly, heads were simply stamped 1 & 2 on the ends corresponding to cylinders 1 & 2 (so opposite ends). (EDIT) Later on the heads were stamped with each cylinder # on the exhaust port flanges (my memories are coming back - LoL).