Based on that photo, your truck has disc brakes. A 63 truck did not come with disc brakes so you need to determine what year conversion kit the previous owner installed. It has to be something from 72 up. Generally aftermarket suppliers won't tell you what parts are used in their kits so you will have to sort it out
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