Is it the engine computer that runs the passkey function, or possibly a body computer of sorts? Find that out. Also, I suspect you're going to realize that the computer chip in your key is actually just a resistor. Assuming it is a characteristic that your engine's computer is reading and not just a go/no go signal from another CPU, then you could fake the value (radioshack resistor) that the computer is looking for on whichever pin the engine computer uses to read that signal.
btw- You are going to become intimately familiar with the new computer's wiring layout. Don't let that scare you, they are fairly simple once you get familiar with what the computer is looking for.
Find a pinout diagram for the engine's ecm.
btw - you might also be able to just swipe the ignition cylinder from the newer car. Then you would still have the passkey function without having to hack in an entire column.
You will want to pay attention to where your accesories are going to be. Making sure they clear steering bits and whatnot. 96...is that an LS1? The good news is that the location of the computer will be easy to replicate on the older car. What this means is that you need the wiring harness from the 96. That will save you from most of your wire splicing work. The only thing you'll be concerned with rewiring is any input that the computer needs from something not directly bolted to the motor (Passkey, brake sensor switch for startup, etc)
You'll also want easy access to at least an OBDii code scanner. Harbor Freight sells a handy one for $40 if you don't already have one. Makes trouble shooting a lot easier. Another device called a Pocket Logger is even cooler to have - it actually tells you the values that the various sensors are sending to the computer...or at least what the computer is seeing. Gives you a quick look at things like TPS wired backwards, O2 sensors out of range or lacking proper crosscounts, airflow sensors out of spec - that sort of thing.
Is this the engine and transmission or just the engine?
