Yeah your probalbly right. 0.3125" vs .215" total thickness, 0.0975" too thick.....it will never work. California metals, not blanchard ground, it will never work.and now it will rip the mounts off the truck! lol my lowers are .125 with .090 overlays and they have been through some shit. my theory was it should be strong enough to take any "normal" abuse i throw at it but will hopefully be weaker then the stock frame....maybe. lol on another topic, where did you get your fixture plate? Is it blanchard ground?