Sorry,,late to the party,,"shim's ",,I use one of those "HIGH ENERGY" cans,,there about .006 thou. thick,,can cut with a pair of siccors. Be sure to hammer the edges down or file the edge's ( they will cut like a razor),,= + -,12 thou.gap,,maybe!!.
If ya' got'm ,,,smoke'm,,(guns ) Hootmix.