Since you are trying to install an RE its an added problem because there are more controls that need addressed.
You have the donor truck so swapping the wiring harnes, ECM, PCM, etc, is going to be the best bet. The ECM is controlling a lot more on a 2nd gen than it is on the 1st gen. Since the 97 is not a STORM block you should be able to swap the sensors and such.
How the feeds to the dash are different and how to do that will take some research though.