I don't think that the gauges are the same cuz i have seen some on a 91 and i have seen some on an 89 and they don't look the same. Remember that the 91 is the phase 2 to the 2nd gen. and it continues from there.
I put a 91 dash in my 89 (yes it fits) But the calibration between the guages and the sensors is different so all my guages were reading wrong (except speedo) and all my warning lights stayed on, so if you exchange any guages for another year
you will also need the sensors for those guages from the same year and engine. The Z24's wont work on a 2.0 or 2.2, so I just put a 3.1 in my 89 base model. It was well worth the cost.