Anyone know if I can get a different speedometer gear for a Spicer 5652 5-speed transmission? It's the stock tranny in my '72 F750 retired fire truck. I swapped out the 7.6:1 single speed for a 5.29 two-speed and everything works great.....except the speedometer. Since I drive in the 5.29 ration 90% of the time.. I'd like to gear the speedometer to be correct while running with that ratio alone; I don't care about the second-speed ratio.

Is there a source for alternative speedo gears for the Spicer tranny?