An 82 Chevette? How about stuffing a rag in it?
That car is truly a junkyard refugee. Go to the car part store and settle for any gas cap that will fit. Stant is OK for your car. Maybe you can just ask for a gas cap from the box of lost ones at the gas service station. Wanting the "best" is a fool's errand.
If you only want the best, then you wouldn't be driving an '82 Chevette.
You call getting a gas cap upgrading?! Just buy one at the dealer dude!
Stock OEM (original equipment manufactures period.
you have try this gas caps