Slider,
Just be sure you get a Chevy automatic trans, GM also produced BOP (Buick/Olds/Pontiac)& Cad transmissions that will not fit a Chevy (without an adapter). However, some of the later ones had a dual bolt pattern bellhousing.
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