well first you have to keep in mind that you're stock springs were not linear rate, so the Man. rating was based off the highest part of the progressive rate. So you're new springs are actually a lot stiffer than your stock ones were,...Some Man. do still use linear front springs, I'm not sure if infinity is one of them. I would suggest backing the damping all the way down to zero and taking a spin and then putting it on full stiff then at least you have some idea what you're working with.

Matt