Deere shows your stock blades for the 54" MOD as TCU30317
The mulching blades are #M144652
This has been a lot wetter year so far than last, so a little more clumping is to be expected. You won't get near as much with the wavy mulchers while the MOD is closed since they don't move as much air, and thus don't compact the clippings into a wad. Plus they redirect most of them back down into the turf while mulching.