Excessive suspension travel

OK, I need some help. I have a 72 Dart, 318, standard supension. My problem is, the right front bottoms out against the lower control arm bumper over just about any bump I hit. All new bushings, shocks, ball joints, etc. Even installed big block torsion bars. The front is set just below ride height (approx 1/2 inch). As I ride down the road the right front travels much more than the left front. Even worse when I have a passenger, which goes without saying. I did replace the new lower control arm bushing just in case I messed it up during the initial installation. I restored the car about 2 1/2 years ago so there is new paint top and bottom. The reason I added that tid bit of info is because there is no evidence of cracked paint where body panels are moving because of a cracked frame. I am at my wits end. Anybody out there have any ideas. Thanks