Speedo gear

As long as your 904 & 833 have the same type of speedo gear adapter, the gear should fit. 66(?) & later or 65(?) & earlier. Not completely sure when the change was made but you can tell just by looking. The later style adapter is a lot larger, like maybe 2" in diameter. Just be sure you index it correctly when you make the swap. There are lines on the adapter that you line up depending on the number of teeth on the speedo gear.