It depends on if you are wondering about steering columns, shift rods, or transmission mounted shift levers. The early 51 is the same in the shift lever department but the late 51 has different levers. There are differences in the early 49 columns and the later 50/51 columns. I've installed the shifter arm bushing kits and re-riveted the levers on on several Merc transmissions. It's a job but the hardest part about it is adapting the replacement parts to work correctly. They use solid brass inner bushings instead of formed brass sheet material and it makes them hard to peen the centers to hold the assemblies together. The shift rods can be straightened and built up with brazing if they get screwy & worn. Mac VanPelt sells some clevis pins that work well to re-rivet the levers back on the transmission cover.