Tom,boy did you just open a can of worms! Our roadster is about 3200# sprung front and back,torsion bars,sprint car or dirt modified style. This question is long been discussed,It all depends on the track surface on that given day. At El Mirage I would all ways run suspension, most years at B-Ville you can probably get away without it.Think about trying to accelerate on cobble stones or pot holes, which would you like then? Our roadster #832 has approx. 4" of total travel front and back. At El Mirage it will use about 2" in the back,and maybe up to 3" in front during a run. I'm sorry I forget the spring weights I will check over the weekend and write back. Hope this helps.
Eric Eyres