IIRC, the hex is based on an early torsion bar car like late 50’s early 60 imperial or something.
The lower control arms changed at some point in late 60’s
I don’t know what your chassis history is. The 1974 Petty Catalog shows a bunch of torsion bars with only diameters listed. They have Chrysler part numbers (that doesn’t mean they were ever installed in production cars)
Then they show 41” torsion bars with 1 1/4” hex and 1 1/8” dia. Those have “PE” Petty Engineering part numbers
Greg K at will know at odcics2@comcast.net
Right ! I looked for those MOPAR part numbers throughout the internet, but nothing came up. On my Petty car, they are of the shorter 37" length. I'd assume that the lower A-Arm's are modified C-Body parts.
