circuit1

I have been putting together a 1981 Camaro that orginally came with a V6 w/AC, it now has a small block 350 with Aluminum heads and intake, AC, headers and a mini starter. I replaced the front coil springs with new springs rated for a HD V8 wAC. The suspension was maxed out resting hard on the top snubbers. I bought a new set of spring rated for a 350/305 with AC and they are just as stiff as the first set. Before I purchase another set can anyone tell me just what I should be looking at for coils? Thanks