All the 85/90 and 120/125 150 came with 20 and 25" shafts.
The 85125 was made through 1989 then they made a 90/120
The lower units to 1993 will swap just make sure before you buy.
The later 94/5 90 120 won't work on the older motors.
Include the year, model and closeup pics of the ones you want to swap.
Thanks Jerry. To measure the inch shaft to make sure if it is 20 or 25", is that the driveshaft (with a long bar) from the top to the gear housing cover? Sorry I am new to this. I wish I can attach the picture, but now allowing it.
Measuring the shaft.
From the top of the shaft to the base of the water pump.
Should measure 20 or 25
After 91 they used an adaptor and all the lowers were the same the change was in the size of the drive shafts.