'71 Cheyenne or CST???

[FrankC]

Hi,
I looked at a 71 SWB Cheyenne (so I thought) today. It had the Cheyenne paint scheme - but when I checked the option list in the glovebox - no mention of Cheyenne. I did find the Custom Sport Truck package option - the number was 1Z84CH. Not sure what that all included.
Does it make it a 71 CST or a 71 Cheyenne??

Lots of options, but came with a 350 and 3 on the tree. Disk brakes (no booster) and air.

Anyhow - I am interested in buying this truck and would appreciate any help from the board on the identification.

Thanks!