The Truck Shop catalogue shows a floor pan with a taller hump for a 4 speed on TF trucks. Likely other suppliers have them as well.
However, I have no idea that this will work with a later auto trans.
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