[1967gto1]

Will this damage the frame or rear end? Do I need to unbox the arms? I took the sway bar off because after researching it, I found that 1967 gto's did not come with rear sway bars. Also, I was at the GTOAA show in Kingsport, Tn. last year and they deducted three points for having a rear sway bar and boxed arms.

[Jeff Hamlin]

As you have found out, the '67 did not have a rear sway bar option as well no boxed arms.
As far as driving with boxed arms and no sway. This would not cause any problems

[Goatracer1]

As Jeff said 1965 did not have boxed arms so they are not correct at a points judged show either. If you are looking for correct you need to remove them.

[1967gto1]

Thanks for the replies.

[6d7gto]

Pretty sure my 67 GTO came with the upper rear arms boxed from the factory but not the lower arms. At least they look original to the car from a layman's perspective. Also had rear end stiffeners (for lack of the proper word). These attached to the frame to prevent wheel hop? 4 speed car built in Baltimore. If someone knows these upper arms are wrong, please let me know.

[Goatracer1]

I have had several 1967 GTOs and have never seen boxed upper arms.

[Sirrotica]

The reason the later cars had boxed lower arms is mostly because they had a rear sway bar. The sway the bar is fastened on would squeeze the lower arms together when the bolts were torqued, and would flex as the bar was working. The only way to use unboxed arms with a sway bar would be a completely different bar, and mounting system, or use spacers inside of the lower arms.

I've been under a heckuva lot of GM 64-72 GM A/G bodies, and I've never seen any boxed upper arms on any of them.

The early cars tended to rip the crossmember out where the upper control arms mounted, especially on stick cars. GM then made the braces that connected to upper pivot bolts to the lower pivot bolts to tie, and triangulate the crossmembers strengthening the whole rear suspension mounting system. I saw plenty of the early cars rip the upper crossmember out, I never saw the ones with the brace system installed rip out though.

Jacking the rear of the cars up really increased the wheel hop problem as it threw the geometry way off, just lowering the rear, would completely get rid of the problem in most cases. Air shocks also screwed the geometry up as they were trying to twist the rear axle upwards in the front because the shock mounts were behind the axle centerline, throwing the pinion angle off. Just the opposite of the way the pinion angle should be for optimum traction.