I am thinking about installing a pair of progressive rate springs on the front end of my 1972 164. I want to maintain the current ride height....which is original to the car. Has anyone done this? What springs did you use? Are the springs on a 140 the same as those on a 164 in diameter, length and stiffness. Even if they are the same dimensions, I may want a stiffer spring than the 140 because the 164 is heavier in front and that would maintain correct ride height. All suggestions, insight cheerfully accepted.