'92 lower unit on a '89 125hp?

[dmas]

Can I use a 1992 dual exhaust lower unit on my 1989 125hp force? , my lower unit it's a single exhaust and it has the water intake on the driveshaft centerline, the one that I want to get it's a 1992 double exhaust and it has the water intake on the gearcase but the shaft, shift link and water pump cover it's the same on the top of the unit, would this give me any trouble? also don't know what single or dual exhaust really means...thanks in advance for your help..