Left and Right SL55 Air boxes, and the Left and Right Inlet Hoses.
All you'll need is the Splitter (P/N 113-090-01-29) and hoses for about $100 from OEMPartsDirect.

I paid $250 for these 2 weeks ago and never used them. I did trim the right airbox so it would clear the oil cap on the C32's.
Best offer over $225 takes them. Includes the OEM Air Filters.

These are larger than the C32/SRT-6 Air boxes, allowing more air to flow in.
This setup showed 15 hp on a C32.

Picture of what it looks like installed: (this set is brand new, in the factory Boxes).