I believe the duster on the cover of the latest Mopar Muscle uses caltracs springs and bars. 1000+ horsepower and the car has not been tubbed OR has had the springs relocated. [but it is not a 4 speed] It's running down in the 8.30's zone in the 1/4 mile. IIRC. FWIW. Back in the old days you just went with ladder bars and sliders. You could also run a reinforced plate and adjustable snubber but I think the caltracs would be better.
