body mount bushings

I just went to reinstall my fenders. I didn't install the bushings under my grill. I am thinking of using solid spacer 3/8" under the grill to split the difference. I will still have to redrill the holes in the fender support where is bolts to the frame. I see a couple of you have used the thicker poly bushings. How did you mount the fenders? And, what about the fender being mounted solid to the frame and the tub having bushings? I suppose the fender is flexable enough.