[Five Points]

First off, welcome to MLF!

Sorry to hear about the motor, I'd need to research that a little unless some else jumps in here. Are you looking to for another 2 stroke or a 4 stroke swap?

 

[Five Points]

I don't now if you have a parts book, but these are listed as alternate engines.
View attachment Snapper cross ref.pdf
If you want something more modern I suggest you measure your bolt pattern, shaft length and size, location of controls etc.

You can contact online companies like tewarehouse.com and they can cross reference your engine to something more modern as well.