mid 90's 75 horse lower unit

[tommyboy]

I recently purchased a boat with a 75 horse yamaha outboard with a bad lower unit. I've found a couple of replacements and was wondering if the lower unit had to be the same size as the engine (for example would the lower unit on a 60 horse bolt up to my engine). Any help answering this question would be greatly appreciated.

[boats.net]

Not sure about the 60hp but 75,85 and 90hp will work.