What else have you changed besides the K member?
I love drag radials, I have run 1.40's on them, but they require a good track to work. I would bet money that they are spinning on the initial launch, which would mean that no matter the spring, they are not hooking enough to lift the front of the car, or make the suspension work. If thats the case, its the track, or the tires.
I predict future happiness for Americans if they can prevent the government from wasting the labors of the people under the pretense of taking care of them. -