Replacing Gauge Cluster 1985-1990 Electra Park Ave

Has anyone ever attempted to replace thee gauge cluster in a 1985 to 1990 Electra Park Ave? My speedometer and gas gauge have given up the ghost and I suspect the cluster as being the culprit. I was wondering what was involved and whether or not I could upgrade from the basic analog to the analog with tach or the digital cluster without much of an issue. If anyone has any experience with this it would be greatly appreciated. Thanks.