* Backspacing: This is the crucial measurement. It's the distance from the mounting surface of the wheel to the innermost part of the wheel. Too little backspacing and the wheel will hit the suspension components or body. Too much and the wheel will sit too far inside the wheel well.
* Wheel Width: Wider wheels allow for wider tires, but again, you're limited by how much space you have inside the wheel wells.
* Tire Diameter: A larger diameter tire will affect your speedometer accuracy and may rub on the fenders, frame, or suspension.
* Suspension Modifications: If you lift the car or modify the suspension (e.g., mini-tubbing – removing parts of the inner wheel wells), you can fit significantly larger tires.
* Specific Nova Model: Even within the 1974 model year, there might be slight variations in wheel well dimensions depending on the trim level (e.g., coupe vs. hatchback).
Without Modifications: Most people who don't modify their 1974 Nova stick to tires in the 235/60R15 or 255/60R15 range, with 15x7 or 15x8 inch wheels. Going much beyond that without modifications will likely result in rubbing.
With Modifications: With significant modifications (mini-tubbing, suspension adjustments, etc.), some people manage to fit much larger tires and wheels, potentially up to 275 or even 295 width tires on 17 or 18-inch wheels. However, this requires extensive fabrication and is not a simple bolt-on upgrade.
To find the absolute largest tire/wheel combo for *your* 1974 Nova:
1. Measure: Carefully measure your wheel wells (including the area where the tire would sit when turning). Note the available space at all points of articulation.
2. Consult Forums: Search online forums dedicated to 1974 Chevy Novas (e.g., on sites like NovaResource.com). People there will have firsthand experience and can share what fits their cars. Be sure to specify your Nova's model (coupe, hatchback, etc.).
3. Experiment (carefully): Start with a slightly larger size than what's commonly recommended and check for clearance at various points of suspension travel. Use jack stands and carefully rotate the wheels to see if there's any rubbing.
Don't try to cram in the biggest tires you can find without doing your research. Improperly fitted tires can cause handling problems, damage your car, and even be dangerous.
