* SM465 4-speed manual: This was a very common heavy-duty manual transmission.
* Allison MT-650 5-speed automatic: A popular automatic option, especially in heavier-duty applications.
* 4L80E 4-speed automatic: Another common automatic, though perhaps less frequent than the Allison in a 1-ton.
To know for certain which transmission is in a *specific* 1992 Chevy 1-ton, you'd need to check:
* The vehicle's identification number (VIN): A dealer or online VIN decoder can provide detailed specifications.
* The transmission itself: Look for markings on the transmission case.
* The owner's manual (if available): This will list the original specifications of the truck.
Without more specific information about the truck, it's impossible to say definitively which transmission it has.
