/6 K-Frame vs. V8 K

Here are the details for the 67 to 72 A-body K frames.

There are several ways to determine whether a 67-72 A-Body K-member is a S6 or V8.​

With the motor in car, measure from the frame rail to the side of perch.

The V8 should measure approximately 4" across.
The S6 should measure approximately 2" across.


If the engine is not installed, you can measure across the top from perch to perch.

The V8 should measure approximately 20" across.
The S6 should measure approximately 22 1/4" across.