cargo springs help with hooking up?

[mobileaudio25]

I have a 250 HP 350 with a 2600 stall and a 8.5 in gn 373 rear end. I'm running 245/45/17 toyo proxes 4 tires which are pretty sticky. I'm replacing all new suspension in the rear and I'm looking for ways to help hook up. Will factory cargo spring replacement be good, or is there a better could spring? Car is strictly street

 

[LS6 Tommy]

I can't see cargo springs being a good thing for traction. They're variable rate springs, so when the spring compresses it has a rate change that will most likely upset the car.

Tlommy

 

[mobileaudio25]

What's a good rear coil spring, and what is a good shock ratio for street use? Thanks for the advice