Imagine an anti-theft gas cap system that's completely invisible. When thieves try to steal your fuel and find their attempts unsuccessful, they will write it off as ornamentation and not worth the time, then walk away. That's why Neal Polan from Affordable Classics came up with his anti-theft gas cap for Mustangs. While classic Mustangs are a specialty, Affordable Classics restores all kinds of vintage automobiles, from muscle cars to the more mundane.
Affordable Classics' anti-theft gas cap system is quite simple, easy to install, and virtually invisible once it's installed.

Neal Polan removes the gas...

Neal Polan removes the gas cap on our '66 Mustang, which calls for a 7/16-inch....

....box end wrench to remove...

....box end wrench to remove the fastener inside the trunk.

A 5/16-inch hole is drilled...

A 5/16-inch hole is drilled at the 8 o'clock position to make way for a new fastener location. The anti-theft sliding pin will go in the fastener's former 4 o'clock position.

Neal bores out the former...

Neal bores out the former fastener hole to 5/16-inch to accommodate the sliding pin.

With the gas cap installed...

With the gas cap installed and centered, Neal drills a 5/16-inch hole from inside the trunk and into the gas cap to....

....give the lock pin a place...

....give the lock pin a place to go, which will secure the anti-theft gas cap.

The Gas Cap Anti-Theft system...

The Gas Cap Anti-Theft system from Affordable Classics includes the sliding security pin, return spring, cotter pin, bracket, and fastening hardware.

Here's how the anti-theft...

Here's how the anti-theft mechanism should look when assembled. The spring returns the pin to the locked position. When it's time to gas up, pull the pin and twist the cap counterclockwise.

Locate the sliding pin mechanism...

Locate the sliding pin mechanism and mark the mounting hole. You will need a 5/16-inch drill bit for this.

The mechanism installs like...

The mechanism installs like this. You will need a 7/16-inch wrench to secure the fastener.

This is a terrific security...

This is a terrific security system that's affordable and easy to install. Even with the trunk open, it's invisible yet effective.

Neal has indexed the gas cap...

Neal has indexed the gas cap so the pin hole will line up with the pin when the cap is secured.

When Neal lets go of the sliding...

When Neal lets go of the sliding pin, it protrudes through the filler neck, which will secure the gas cap. Just twist clockwise, listen for the click, and feel safe about your fuel.