I would say 120-130 lb/in is the ballpark you should be looking in. The exact rate will depend on how your car is set up, what the weight balance looks like, what front torsion bars you’re running, and what tires you have. Lots of variables.
But the folks that do road tracks and autox, like Peter Bergman @BergmanAutoCraft, Hotchkis, and even Mopar Performance with their oval track springs, all have springs in the 120-130 lb in range.
