Real wheel hop during braking

[E30M30]

Hi

Finally I've driven my firebird at a track. It's a '67 firebird with hotckiss lowering springs with red koni dampers at the front. And multileafs with konis in the back. I'm running 2002 camaro brakes front and back with adj. valve for the rear brakes. At the end of the straight my rear wheels starter hopping all over the placed (quite scary). Unfortunately I'm running traction bars (I know they're not designed for corners) What should I do to stop the rear wheel dancing By the way the suspension is rock hard - should I adjust the dampers?

Best Regards from Denmark/Europe

stefan