I'm guessing as a start (no doubt I'll be corrected by those who REALLY know!)
Evinrude/Johnson 75 1960-1965
Gale 60 1960-1963
Evinrude/Johnson 60 1964-1967
Evinrude/Johnson 80 1966,1967
Evinrude/Johnson 65 & 85 1968
Any "Heavy Duty" lowers were the one from the 50hp.
SOME of the above were available with both electric & mechanical shift.
You can look at the years here:http://www.marineengine.com/parts/johns ... -parts.php
Which will give you model numbers (tho I'm sure someone has a faster way!)