Speed tech rear coil spring rates

[TANKMASTERJ]

So I've got a speed tech track time front and rear setup in my 67. Rear torque arm came with aldans it's older. Front sub came with vikings.
Rear shocks are leaking so I'm upgrading to ridetechs
What coil spring rates should I do? I asked speed tech and they said 300. Seems a bit high. Thought I'd post here and ask
Thanks!

Jason

[SPG]

Depends on how much the rear of your car weighs and how you're using the car.

Here is a general rule of thumb for another torque arm style suspension setup
214952

[TANKMASTERJ]

I'll have to weigh my car this weekend. Hoping for a 49% rear and 51% fro nont bias. Car is estimated to weigh 3500. All aluminum LS7 in front and has twin batteries in trunk.
Whatever the speed tech older torque arm with aldans came with it bottoms out. I don't know what rate they were as I bought it new in box but 10 years old.