It sounds like a lot of work and expense for minimal gain. Your disc brakes on the front provide over 60% of the braking. If the system works OK and you don't do any serious hauling it should be fine the way it is.
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