* 700R4 4-speed automatic: This was a very popular choice for that era and engine.
* TH400 3-speed automatic: Less common, but possible, particularly in heavier-duty models or those with specific options.
* Manual transmissions (various): Several different manual transmissions were available, but pinpointing the specific one without the vehicle's specifications (like the RPO codes from the glovebox sticker) is impossible. These would likely be 4 or 5 speeds.
To know for certain, you'd need to check the vehicle's documentation (owner's manual, build sheet, or the sticker inside the glove compartment). Looking at the transmission itself (checking the casting numbers) is another way to identify it definitively.