I've been trying to see if I could find the spring rates in the descriptions on mopar parts sites... Normally they're described as "600 lb" or something which is just a standard measure at a certain deflection. For instance a 500lb spring would have a lower spring rate than a 600lb spring.
Where are you in NY? If you're interested in the setup, it may be worth just trying them out; especially is you could use new struts to start with
Edit: but you better start spraying those lower fork bolts with PB Blaster now!! lol