The rear end depends on what series truck. If it is a 3100/3200 (1/2 Ton - 6 lug) it would have a 3.90:1 ratio. If it is a 3600 (3/4 ton - 8 lug) it would have a 4.57:1 ratio. Both are corporate GM rears. A one ton would have something like a 5.12:1 ratio.
Fred

Last edited by rfs56trk; 03/10/2014 4:47 PM.
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