Hainzy

On HZ commercial, special vehicle package XW5 "country pack" got you:

F72 "Gross Load Equipment" - heavy duty rear springs (tonner springs).
K45 "Heavy Duty Air Cleaner" (only with 6cyl).
D71 "Rear Mud Flaps"
T57 "Front Mud Flaps"

And feature changes:
Engine splash pan
Rear shock absorber stone shield.