Coil spring question/help

[XcYZ]

I'm posting this for a friend who has a 70 Camaro with a big block. He wants to lower the front of the car yet keep the spring rate close to stock (close to 300lb I believe). From his research, the lowering springs that he's looked at have a much higher spring rate. His car isn't a g-machine, it's a street/strip setup and wants to maintain the current ride quality.

Any help or insight would be great.