direction of oil squirt hole in rod

Just checked my 73 slant 6 connecting rods on my original never disassembled engine - the oil squirt holes are pointing towards the cam shaft. I'm in the process of taking it to a rebuilder. I will talk with them to make sure they know the correct direction of the oil holes, we shouldn't take it for granted that they possess this knowledge.
The small slots on top of the pistons all face forward. Is this just another indicator that is used to insure the connection rods are installed in the correct direction or do these slots serve another purpose?