I ran a 833 in an alum overdrive case for years so I'd assume that you could reverse it and put OD gearset in a cast iron 833 case. Hopefully that's not what's going on here. Been so long but the OD flips 3 & 4 so if you are truly seeing an overdrive condition when you are in what's supposed to be 3rd that may be it. Hopefully all this is not the case for you and just a fork issue.