Welcome to the forum Adam. It sounds like you have an interesting project there. You are going to find out that the way the 97/98 pcm controls fueling is less than an optimal way of doing things. You've come this far with building the motor...I might suggest one more step, swap the pcm. For the Vette, it is a 160 pin swap right at the pcm connectors- the serial data line is already pumped into the cluster, unlike the fbody.
Here is a pictorial of what you need to do....
http://www.efialchemy.com/db/02to97pcm/02to97PCM.html