not sure about 65 but I know 85 and 115 interchange - the '70 and '71 115's had a different gear ratio but think '72 and later they were 2:1 ratio. A different ratio will work but may require a prop change.
Early 70's until the end of inline six motor production should interchange w/o issue. A lot of IL4 motor gearcases will fit, but have different gear ratios
The answer is no all the 4 cyl 650/850's are a 2:3:1 and the 150 is 2:1. Some people say it will work by raising pitch but it makes it a dog on low end...works the same when a 2:1 is install on a 4 cylinder. The only ratio different in 70-72 is the 1350 as its 1:78
