I have a 1969 50hp 500. And I was wondering if a lower unit from a earlier model 50hp 500 could fit. My drive shaft is screwed and I am having a problem finding a replacement so I went and bought a lower unit complete but the problem is that this new lower unit is the type that has the Preload Pin in the top of the driveshaft and my other one did not. The lower unit itself looks a little larger than the old one (not by much) and It looks like I have to redrill one of the Exhaust housing holes that one of the lower unit studs go into. The Impeller and water Pump is the same for both ( except the the new water pump housing is plastic and my older one looks to be metal. Everything else looks to be the same though, so I was wondering if there is anything that I should do to prep this? Oh yea does anyone know where the serial or part numbers are located on the Lower Unit? I hope this is not too much to ask? Thanks and have a wonderful day
