Lot's of variables here. It could depend on what engine and transmission combination
you currently have.
A 3.73 rear end would have to come from a later vehicle which would require some
spring pad relocation and driveshaft mods. It wouldn't change much from the 3.90
standard gearset in the truck.
There is a 3.38 gear set available for the corporate Eaton that came with the truck.
There are factory overdrives and later units available using the stock rear end.
I believe in disc brake upgrades, there are 6 lug conversions available.
5 lug conversions will require all new wheels and possibly tires.


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