I am thinking about Nut Zert's for bracket and mounting TAC or welding or gluing a solid 3/16" or 1/4" piece aluminum to backside of bracket and tap thru that.
Oh no don't do that, that piece will scar the dashpad.
You could tack-weld it on top and grind the underside smooth tho. Just make sure the two pieces are welded tight cuz the tach will bounce around pretty good., eventually breaking inadequate weldment.
