A factory overdrive transmission is available for that series truck and you don't have to modify anything. Some electrical components are required. Better performance, highway speeds, and less stress on the engine. 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
