I bought mine from king springs. Good quality. Expensive. Used 75mm ones too fit the diff housing and they did need trimming. And where m10 so didn't have too drill the backing plate. The #OOPS#ty lowering block kits use imperial I think so needs too drill the backing plate out. And the u bolts stretch alot. Can't ever seem too get a firm tension. The kings spring u bolts where High tensile so didn't stretch alot and tensioned up well.