I believe the stock drums had a punch out slot but you have to remove the wheels to get to it. If they are aftermarket drums, probably not. I think they stopped having a slot in the backing plate in the late 60's depending on the vehicle.
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