Corvette C3 birdcage and rust
Although the body of the C3 Corvette is made of fiberglass, rust can be found on the body or in the birdcage, which can be difficult to notice.
The birdcage refers to the metal frame that surrounds the Corvette's cabin and supports the body panels around it. The same birdcage and frame were used throughout the Corvette C3 generation.
Rust problems are often around the windshield and pillars, as well as the mounting points of the birdcage and the radiator core support. Perhaps the most critical place to look for rust in a birdcage is the frame mount points, which can be inspected from the passenger compartment behind the kick panels.
1975 and older Corvettes had fiberglass floors, so there was no risk of rusting, unlike the 1976-1982 cars, which have a high chance of rusting due to leaking T-Top weatherstrip.
When you are buying a C3 Corvette for yourself, it is important to check for rust problems, as they are generally the most expensive things to fix. I recommend checking out the Corvette C3 Buyer's Guide from Corvette Ben and Cletus.Ten Rules For Buying Your First C3 Corvette
C3 Corvette Buyer's Guide
Remove the door sill plate and the kick panel in the footwell, from there you can see the birdcage and frame fixing bolt and part of the birdcage.
With a headlamp, stick your head into the footwell and look straight up, you can see part of the birdcage from there.
Remove the rear tire and open the small hatch in the wheel housing, from there you can see the vulnerable part of the birdcage, which is the frame part in front of the rear tire.
A-pillar i.e. inspection of the windshield frame. The metal of the A-pillar can be seen from the outside at the edge of the windshield.