Exhaust for Vanguard 16hp

Anyone know how to find the right part number for a muffler on a Briggs Vanguard 16 hp engine? Looking at the Vanguard parts manual for the engine it lists multiple mufflers and even has an exhaust 1 and exhaust 2 section. Can't seem to find anywhere how to tell if my engine is 1 or 2.

Engine model/type number is 303447-0447-01. Code 94121311