1985 mercury 150hp black max driveshaft

[tommytwogunnz]

I have a 1985 mercury 150hp black max with a broken driveshaft. It does have the preload pin on the top. I have found another lower unit with the same number of splines on both the driveshaft and prop shaft. The gear ratio is also the same 2:1. However, the other lower unit does not have the pin on top. So obviously my question is it work properly if I mount it up? What is the difference between the two (other than the obvious fact of the preload pin)?

 

[wired247]

As long as its the shaft that came with the lower you are OK