Assuming they don't chekc the block's code...
AFAIK you don't need the OBD2 dizzy, you can repin the connectors. The z6 dizzy is the only thing that fits it with more than 1 bolt. Then you need to add the crank flux sensor. You'll have to do some hacking, since you do not want to swap on a y8 oil pump & oil pan to get the sensor the normal way. You'll need to find the exact spot, fab a bracket, find a y7/y8 crank gear, then cut the timing cover to fit the mess down there. If you can simulate the sensor successfully, that would obviously be the better route. The PCV setup will be a little different, but that can be dealt with. Beyond that, there's not much else to do, unless you have the z6 IM and a 3-wire IACV.