All stock TWs have a spark arrestor in the end of the muffler unless some foolish PO removed it.
O Ring and X ring chains are very much superior to the stock chain. The rubber rings, O or X go behind the joining plates and seal the roller bearings from outside water and dirt getting in and this is where 90% of chain ware occurs. Ringed chains are pre lubricated and need very little external lubrication. Where a stock roller chain might last a few thousand miles and require constant adjustment and lubrication/cleaning the ringed chains should last at least 10,000+ miles with very little adjusting and lubing. Chain ware directly relates to sprocket ware so by upgrading to a ringed chain you get the added benefit of longer lasting sprockets.