The SM318 transmission has the same internal gears from 55 through 65 for cars and 67 for trucks. There was a Corvette version and a Pontiac version but it unlikely you will run into one of those.
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