Originally Posted by RSM
You can look up a company called Caltracs ( http://calvertracing.com
) . They sell a real nice traction bar setup for leaf spring cars. On average they run about $350.00 and work very very well.
Similar devices are made by Competition Engineering (the Slide-a-Link) and Smith Racecraft (called Max Trax).
A simple but properly built Slapper Bar (again Competition Engineering, only company that makes these correctly) may work for you if this isn't going to get sticky drag tires.