I set this display up (see below) so you can see the difference between the three styles of lower control arms. They all fit 1964 thru 1972 GM A-Body cars without alterations of any kind.

The first style lower control arm (the one in the center) had round bushings on the front and rear of the control arm. They are correct for 1964 thru early 1966, the front bushing measured 1.67 inches and the rear measured 1.90 inches and had a double metal inner sleeve.

The second style lower control arm (the one on the left) also had round bushings on the front and rear of the control arm. They are correct for 1966 thru 1972, however the front bushing measured 1.42 inches and the rear measured 1.67 inches.

The third style lower control arm (the one on the right) had a round bushing on the front and an oval bushing on the rear. They are also correct from about 1966 thru 1972, the front measured 1.42 inches and the rear was an oval. These were also the replacement part for GM on all style lower control arms.

All three styles are interchangeable and fit all GM A-Body cars 64 thru 72.

The general belief is the round bushing provide firmer and better handling but the oval bushings are more prevalent as they were the replacement part supplied by GM. The conscience of this is the round bushings demand a higher price.

If you click the pictures below they will enlarge