the 16181333 has a few extra chips that probably help with some prototype OBD-II emissions testing stuff that is not available in the 16188051.

this extra stuff wont affect you in real life and in reality was never used by GM

you do have to reflash the 8051 first or it wont work on the bus with the CCM (the 8051 by default is the bus master, but in the corvette the CCM is the bus master)

reflashing the 8051 in the car might require you to pull the fuse for the CCM until that first reflash is done?