The 90-93 cars had air bags so there is a slight hump at the bottom the gauge on the air bag cars. The 89 140 mph speedo has the straight bottom and I know is a plug and play for the early foxes. The later clusters 90-93 are wired different than the early gauge cluster I know for sure, they change the warning lights around and added the air bag light so this could pose a problem for plugging it in and have all of your functions working on the older cluster.
The 90-93 cluster can be fitted into non airbag car with a little work or you can swap the speedo itself out of the newer cluster into the older cluster but you need tp remove the needle and overlay. The other option os to source out a '89 cluster from ebay, junk yard ot places like prestige mustang parts.
you can always try and plug it in and see it may work I'm just going off of pasts memory on the subject, although I do know for a fact about the hump and moved warning lights.
1991 GT 5.0. clean & mean
'08 Explorer E/B
'11 Lincoln MKX
'00 Contour modded/tuned
'01 Suzuki Bandit 1200S