You're thinking of the filter boxes. The air silencer box (what I need) goes between the filter boxes and the carbs. It's the large box mounted right on top of the engine when you lift the bed.
There's 1 on ebay right now, but if you think $80 is pricey, you're gonna hate the $200 he's asking for it.
I use this mule at a 501(c)3 nonprofit museum, so I have a hard time affording that.