If you decide to go with coil overs, call the company you get them from and tell them what they will be used on and how it will be used and they will tell you the best spring rates for them. I used QA-1s on my Cobra but it had a stroker in it and never weighed as much as yours does. However they did recommend that since I was driving it hard on the track to go with a stronger spring than if I was just using it as a cruiser. As stated the coil over are more expensive and if you don't race the car probably aren't worth the extra money. But they do make it easy to adjust ride height and rebound.
Ron
