I think that only the malibus will work . montes and regals are a differnt shape and design, you may have to take the whole peice of dash ( houses gauges) and bolt it in place of the original. I dont know if it will fit. Keep an eye out for an iraqy malibu (4 door, 6 cylider, 4 spd, stick) They had a speedo that went to 200 mph. it is something that most people dont pick out but it makes a trick addition to your ride. It is an easy swap and it is usually an item found at a wrecker. I may even have one , but i would have to check. [email protected]
Hold on to that vine, Tarzan, that is not as true statement, but close. The 78 Malibu has a sweep speedo, where as the rest have a dial speedo, like a round gauge. If it is a round gauge, you are in luck because Tarzan speeks with unforked tongue. But if it is a long retangular one, only 78 Malibu will fit. And before you ask, to change out the entire gauge cluster, it can be done, but you need new sending units.
Take two aspirin and call me in the AM