has anyone used the kit from riff raff diesel ?? they advertise it , so you assume it a ford part .. but when it arrived it was obviously aftermarket.. that in itself make me leary .. I have heard of some springs being way to strong , as compared to the ford blue spring.. any feed back , or comments would be appreciated.. I know theres lots of good aftermarket products & that ford surely isn't always the best way to go.. many of you are far more schooled than me in these areas.. thanks..