I can confirm, it is PN 19207665 for the L99 version which lines up with the truck accessories. Apparently the LS3 version is also driver's side outlet, but shorter and does not line up with the truck accessories.
Here are some pictures from my thread showing the pump that I ordered under that part number.
Originally Posted by -TheBandit-
Here are some pictures comparing the LY6/L92 truck waterpump to the L99 Camaro waterpump. The belt contact area of the L99 waterpump pulley aligns perfectly with the truck pulley, despite the overall size of the pulley being shorter. On the backside, there is plenty of clearance for the VVT timing cover, which I assume is the same between the LY6, L92 and L99.
On the engine:
The driver's side, forward outlet should make hose routing cleaner for my Nova's driver's side inlet radiator. This may restrict belt routing options for driver's upper accessories if not using the L99 accessory configuration. I will try bolting the truck accessories up to see if they would work with alternate belt routing, even though at this point I don't plan to use them.
On the passenger side, you can see the bosses for mounting the L99 tensioner are thicker and stick out further, so the LY6 tensioner will not line up.