Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Hey!
This is a great group!  I have a very old Snapper rear engine (Bought used from my brother in law in 99 and he said it was bought 13 years before.  I don't know if it is true as a mechanic told me it was an late 80's model).  I don't know the model number but it has a 12 hp Briggs and Stratton engine.  It needs replacing.  The rest of the mower is in good shape with an exception being it doesn't cut level.  That's easy to fix but will accept any recommendations. 

Someone told me once that the Snapper has a different shaft from other mowers and just any engine wouldn't do.  Is this true?  If it isn't true what engine would work best?  Can I get anything off the shelf or do I need a special engine?  It would be nice to up the horsepower but price is important.  Used is fine with me as money is an issue. 

If model number and such is important I will get them and post later.

Thanks for any input you may have!

Jeff