You have to add a tps (throttle position sensor) onto the carburetor.
This video at 2:00 mark shows a guy that did his - he doesn’t cover good detail but enough to show the idea.
Summit, Jegs, etc sell the tps kits for different carbs. Get your carb make, model first then Call them.
If money is tight- you need to be resourceful and adapt the tps from your old throttle body onto the shaft for the primary butterfly of the carb.
Post pics of the carb and tps and maybe we could give suggestions but it generally would involve building a metal bracket - imitating what the hotrod shops will sell.
Welcome to the site BB.
It is not real difficult to build a bracket to screw the TPS to, the challenge comes from getting the throttle shaft to accept the TPS.
We do like some pics if You could possibly post some for us.
Your speedo was operated off of a 4k pulse per mile 5 volt square wave signal from your 97 black box PCM. Some trans controllers can provide a suitable output to run the speedo, but most go and get a vssb off of a 93-95 truck and install that to provide the signal for your speedo as well as the 128,000 pulse per mile abs signal.