Can't speak to the air grabber plumbing as mine doesn't have that. Could be that they used a three hole grommet, I just don't know.
I've attached a photo (hope it get there)of the grommet for my car.
Also, if indeed yours takes a vac actuated heater control valve located on the passenger side inner fender; be aware that the oem style that is made of phenolic, though correct, does not last long in the very hot environment near the exhaust manifold (especially with a 440). I've gone through three of those types and finally settled on the better all metal style which is still correct but less widely used.
Well, I tried to send photo but no go. Having difficulty figuring how to attach photo file. Sorry