The Truck Shop catalog shows a 54-56 switch and a 57-59 switch. Brothers has them also. The only difference would be the angle of the lever for the flat vs the dished wheel. You should be able to use the cancelling plate as well.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine