Well, ya have to keep in mind that the springs were originally developed for the fox cars. We are asking them to work on cars that have some differances as far as weight distribution, suspension geometry(I assume), etc.
Maybe I am just to anal about how the car sets. To be honest, the initial measurements I took showed that it was off from one side to another with stock springs. I just never noticed until I put a tape on it. I would have to say that I would consider the "C" springs, only because when I sit down in the car it is dropping a good 3/8"or more. I think the "C" spring with its higher spring rate would prevent most of that from happening.
I can say this though as well......knowing what I know now, since it looks like I will have to buy C/C plates anyway due to the drop that I was trying to avoid, I would buy the Eibach springs. That is the only reason I bought the FRPP springs...... because of the ADVERTISED drop.