Chevrolet used various rear axle ratios and types in the 1967 Chevelle. Without knowing your specific axle ratio and type, I can't give you a definitive answer.
To find the correct weight:
1. Identify your rear axle ratio: This is usually stamped on a tag on the differential housing itself (look underneath the car). Common ratios include 2.73, 3.07, 3.31, 3.55, 3.73, 4.11, etc.
2. Identify your rear axle type: This is also often stamped on the differential housing, or you might be able to determine it visually (10-bolt axles are common, but 12-bolt posi-traction axles were also used).
3. Consult a Chevrolet parts catalog or a reputable online resource: Once you know your axle ratio and type, you can look up the recommended gear oil weight. The weight will be specified as an SAE number (e.g., 75W-90, 80W-90). This often depends on the climate where the vehicle will be operated - a thicker oil (higher number) may be preferable for hotter climates.
4. Check your owner's manual: This is the best source of information, if you have it.
In short: Don't guess. Finding the correct information based on your Chevelle's specific rear axle is crucial to avoid damage.
