[captainrb]

Buster.. the easiest way is like the other guy said Smart racing has a special bolt and nut set up.But expensive. Wevo part number 552160 and cost $99.65 . I had same problem with my '73,when I replaced my steel trailing arms with aluminum ones. I used a grinder and beveled the head and the shank. I lost only a little on the head due to beveling maybe 10% of the flat area of the head. It is my option that this is a good fix and bolt strength is not reduced.Somehow altering this tourque tube may cause trouble down the road due to torsion bar chafing. Good luck.