I need someone who knows rear spring rate for elkys. I have a 72 and it currently has a big block in it, but came with a small block orig. I need the factory small and big block spring rates for rear springs. I need to buy a set and I drag race, so if you just buy springs to buy them from hearsay, then keep moving, I need GM rates if someone has them or the info trail to them. Thanks to all who reply and I don't mean to sound cocky, just need the correct GM info for the correct spring needed for my drag truck. I am not buying GM springs but I need to come close to the rates for my launch.

Have a great season, what's left of it :D :( :( lots of rain in the motor city and the Woodward dream cruise still went on even in the rain. Saw some awesome big tire elkys too, very cool to see them set up right.

Elkyman
John :D

i believe it was 135

If your main concern is launching then what does it matter what GM used?

GM selected spring rates based on versatility, customer perception of ride quality, load variance, and compatibility with front end suspension parameters.

You have none of these constraints in a pure drag launch situation. Shoot you probably want different rates left to right for that.