[Dwight Southerland]

There were two different subframes in production 1967 Camaros and Firebirds. A light one was used in cars with 6-cylinder engines and 327 engines. All others used a thicker frame for the additional weight and stress. The light ones did not have holes stamped on the inside the front of the frame horns, the heavier ones did. Production efficiency and volume production economy dictated changing to using only one frame around June, 1967. That was the story I was told by a Chevrolet engineer around 1979. Actual weight difference I found was 12 pounds between two frames I compared.

The light frames did not have holes drilled and tapped for front sway bar.