348 rear bumper mounts

I'm just about to reinstall my rear bumper and noticed in the parts book the existence of shims between the rubber spacer blocks and the body. Previously my Capistro was pushing against the bumper, chafed through the foil heat blanket and was bubbling the paint below the license plate. The parts book shows two shims on each side between the rubber block and the car body ( US Market). My question is does anyone know how thick these shims are ? Mine were all missing...... thanks, JGW

 

Apparently not much interest in this subject so far. I find this curious as I'm sure I'm not the only one who has had the rear bumper off. My own experimentation so far has been to add two 1/8 inch shim plates to each main mounts on top of the thick poly blocks. Considering the car was missing all shims originally .... I took a guess and it seemed to at least relieve any "pressure points" ie hot spots with the muffler. Note that I'm trying to clear a Capristo system. I have re lined the bumper back side with new reflective heat blanket material and plan to repaint the lower exterior of the bumper due to previous heat damage from the muffler. I am still curious if anyone can provide a dimension of an original "Ferrari" shim. I can see the original mount "build up" was discarded by who ever installed the exhaust.....Just something to be conscious of if you see your paint bubbling under the plate....