Small Engines (Lawn Mowers, etc.): Tecumseh 3.0hp SnowBlower Head Gasket, blown head gasket, problem diagnosis

Question
I have a SnoChamp snowblower that would run for a while then quit almost acting flooded.  I went through the bowl of the carburetor and finally took the Head Off and found a blown head gasket.  This engine has 3 bolts on one side and although mirror imaged on the other only locations for two.  It blew between them.  My question is where can I get material to replace the gasket?  Also, does it make sense the symptom/problem diagnosis?  Head gasket blown, oil blowing out and covering the coil preventing consistent spark, then starting to miss eventually stopping?  Thank you.

Answer
Replacing the head gasket is easy...take the numbers from the engine into a dealer.  Then make sure you clean the mating surfaces without damaging the aluminum.  Check the head for flatness with a straight edge.  It is possible this "blowby" was contaminating the ignition coil but would really only affect it if the coil has a crack in it.  I would check this thoroughly (visual).  It's also likely that the compression loss becomes greater as the engine warms up and this causes running problems.  Hope this helps.