1979 Johnson 70 hp lower unit compatibility

[zino]

I need to replace the lower unit on a 1979 Johnson 70 hp outboard. What years and hp OMC motor lower units are compatible. Any info would be much appreciated.

 

[racerone]

From about 76 to 88 they are interchangeable.----Only the 60 / 70 HP and possibly some 65 HP commercial unit of those years and those years only.