1971 Johnson 40hp Longshaft lower Unit interchangeable years?

[Jewell]

I inherited a 71 Johnson 40hp electric start with a bad lower unit. Can someone tell me all the years that are interchangeable with this one.
Thankyou, Jewell

 

[racerone]

Some of the earlier 33 HP units might fit.

 

[racerone]

I know that the 74 / 75 / 76 models used a bigger diameter driveshaft.

 

[racerone]

Do you have the 5 inch extension housing ?-----Your location?

 

[fdrgator]

Yeah, earlier 28hp-33hp Johnson & Evinrude, and Gail-built 35hp-40hp models. Heck, even some way back as far as 1955 will bolt up but you have to be careful of internal differences.

Pre-1971 J & E 40 hp won't work..