I am trying to figure out the proper method for mounting the vacuum servo for the cruise control. Car originally did not have cruise, so this is a pictures and wiring type install. I drilled the holes in the firewall for the servo bracket, but the bolts do not appear to be self-tapping, nor are they of a thread pitch that can be done with a normal tap (very coarse threads). Dealer microfiche doesn't show if there are any nuts on the passenger compartment side of firewall, so I'm stuck right now wondering what the proper procedure should be. Any help is appreciated.

Jeff