yes on my car the ac vacuum hole has a grommet in it ,mounted with 3 screws.my grommet has 2 holes in it,one hole has a bit of hose molded in it,thats where the water valve cable goes through.hole 2 is for vacuum source,on my -70 cuda it goes to a nipple at the rear of the carb base plate(holley 4367). other cars has only 1 hole in the 3 screw grommet,for vacuum source.those cars has the water valve cable coming through the insulation retainer hole next to the clutch safety switch hole. theres a good thread about this somewhere on here.one thought on that thread is,manual brakes =2 hole grommet? if i remember right no one came up with a final answer to why there are 2 versions.
