4 link rear with coil overs?

Anybody running 4 link rear with coilovers? I'm curious what spring rate guys are running my coils are mounted at 18 degrees with 200lb springs and I think they are to light. I was thinking about going to 250lb springs but was hoping somebody has some experience and would chime in. Shocks and springs are QA1 adjustable with 2.5" x 10" springs on a 64 Barracuda.