I have a 1985 cutlass ciera that has the standard cluster w/ odometer & fuel gauge. I was wondering if theirs a way to replace it with the rally sport cluster that came on some cieras in the late 80's that have odom., tach.,temp.,battery,etc. gauges on it. The salvage yard I live near has about eight cieras that have the rally sport cluster and I wanted to get one if this can be done somehow. Also my cluster has the speedometer cable and all of the ones at the yard are electronic, so can that be changed somehow as well? I noticed that on the back of both cluster models that the two connections look the same like it would just pop in place, but i know that some kind of wiring or something would have to be done in order for it to work. If anyone out there knows if this can be done please don't hesitate posting it here, i'd appreciate it!

The quick and dirty answer is no.
Sorry, there is more to that swap then hooking the new on up. A factory Service manual would show the difference.