We've had a problem with front end shake in the shutdown area for the last 3-4 years. Car is a 64 Dodge Polara, 493 wedge, 727, 4.10 Dana, runs 9.90's-10.10's at 134. Car has monoleafs, Calverts, tubular upper control arms from Bondo Bob, quick release centerlink bushings from Roth. It has been set up this way for the last 10+ years. Since this problem started, I have changed the lower control arm bushings to polyurethane, new idler arm, new Calvert 90/10 shocks, increased caster from 2 to 4 degrees, reinforced steering box mount (added a strut), pitman arm is tight, center link has no play, toe is +1/16" to 1/8", front tires rebalanced (does it with other tires too), front brakes sent to Aerospace to be rebuilt, rotors checked for runout. It has some front end shake in the shutdown area from about 100 mph to about 60. Seems to be going into a resonance where if something is done like wacking the throttle or hitting the brakes harder will stop it. Competitors have noticed the front wheel bouncing in the shutdown. Drives fine on the track, problem is just in the shutdown. The only thing we haven't changed are the torsion bars (6 cyl; adjusters are cranked in pretty far) and tried a stiffer shock. Any thoughts? This is driving me crazy.