Rear coil overs

[d64falcon]

I put rear coilover on my 67 Mustang dragcar for the first time and i want to know if i picked the right weight spring.

I picked a 125# 12" long spring. I installed them at 11.5 inches and they are at 8.5 inches with me in the car. I will be racing the car for the first time with the new springs tomorrow.. When i push down on the back of the car it has a inch or so bounce and softer then the leaf springs i replaced. the rear of car is around 1300# (havent scaled after the changes)