If it will fit, and the engine isn't blown and doesn't have a sick bottom end (crankshaft, rod bearings, main bearings) it isn't likely to be expensive to fix. I don't know if they had the usual choice of two crankshaft lengths on that engine (I don't even know its type number). You could just ask the seller for the diameter and how far the crankshaft extends below the engine's mounting face, then make the same measurement on your blown engine. You would be getting an older-style side valve engine in place of an OHV engine, which means it will use more fuel, but it might be a bit less tender as well.
Do you feel up to doing a bit of exhaust pipe and muffler work if necessary?
