87 Daytona Shelby Z spring rates

I am looking to purchase a set of BC Coilovers for my 87 Daytona Shelby Z. Years ago, I installed a set of P4452205/6 springs on my 94 Sundance. I could get up on 3 wheels cornering, but it rode like a solid tail chopper. I don't want to hurt the ride quality on the Daytona, I mainly am interested in the easily adjustable ride height. From what I can see, the weakest springs offered are rated at 336 lb/in. Given the terrible ride I had with the auto-cross springs at a supposed 200lb/in front 275lb/in rear, what kind of ride should I expect with the coilovers?