* C6 3-speed automatic: This was a very popular choice.
* FMX 3-speed automatic: Less common than the C6, but still a possibility.
* 4-speed manual: A manual transmission was also available. The exact model number would vary, but it would be a four-speed.
To know for sure which transmission was on *a specific* 1983 Ford F-150, you'd need to check the vehicle's documentation (owner's manual, build sheet if available) or look at the transmission itself for identification markings.