“Reset clutch to unworn position”

Hi, I am getting ready to replace the clutch in my pickup and was reading through some instructions on how to do so, but I have 2 questions:

1) How do I determine the model of transmission that is in my truck?

2) Once I’ve found that out, this may or may not apply, and if so, I need to figure out what this entails: “If equipped with a NVG 4500 or a ZF S6-650 transmission, and ONLY the clutch disc is to be replaced, the pressure plate and NEW disc must be “reset” back to the “unworn” position.

So this only applies to those 2 types of transmissions, but I don’t know what my truck has in it.

Vehicle info:

2004 Chevrolet 1500

V6 4.3L MFI (LU3) VIN X


VIN: 1GCEC14XX4Z324312