* 4L80E: This 4-speed automatic was very common in the K2500.
* 460LE: Less common but possible, this is also a 4 speed automatic transmission.
* NV4500: This is a 5-speed manual transmission.
To know for sure which transmission is in *your* specific 1999 Chevy K2500 4x4, you'll need to check:
* The owner's manual: This is the most reliable source.
* The sticker on the driver's side doorjamb: This often lists options and may indicate the transmission type.
* The VIN: You can use a VIN decoder (many are available online) to find detailed specifications about the truck, including the transmission.
* Look under the truck: You can visually identify the transmission by its shape and markings. However, this requires some familiarity with transmissions.
Without more specific information about your truck, it's impossible to say definitively.
