* Three-speed manual: This was a very common option.
* Four-speed manual: Also a popular choice, offering more versatility.
* Three-speed automatic (Turbo Hydra-Matic 350 or TH350): A widely used automatic transmission.
To know for certain what transmission is in *a specific* 1972 Chevy truck, you'd need to check the vehicle's identification number (VIN) and/or the build sheet (if available) or look under the truck itself.