This uses a v-twin engine. The original engine used a 1" diameter shaft. You can use your muffler, alternator, and regulator from your original engine on one of our new ones. If you use the 356447-0079 engine and you drive of the flywheel side of the engine, you will have to use your flywheel and shroud of the old engine as the 356447 series engine is about 1-3/8" wider than the 350447 series. You may have to use parts of the old engine for this to work for you.