35hp mercury lower unit

[bass_tracker]

Need help again will a 70's model lower unit fit a 1964 35hp mercury?? I know it will fit a lot of year models but i don't now it it will go that far back. thanks for any help.

 

[bass_tracker]

Both motors are 35hp

 

[hotrod53]

Measure shaft length, count shaft splines, see if they both have or don't have preload pins. If those are the same, it may fit. One of the Pros can address if there is any ratio differences. I replaced my '77 500 lower unit with who knows what it was off of.