Idle air screw location.

[alpina]

I have seen on various cars the Idle air screw in different locations. Mostly to the front of the engine closer to the air cleaner. However i have also seen it located at the rear
of the engine closer to the firewall.  Why would be fitted in different locations? does if matter ? having at the rear there is a longer hose from the air cleaner. Is there any
advantage in it being in a certain location?  The W108 280se it tends to be at the rear.
I look forward to your thoughts.

DM

[ja17]

When it gets crowded in the front of the engine, with AC etc., then the rear location is often used. The engine seems to run and idle fine with either location.

[Tomnistuff]

When I added an AC compressor to mine with a sedan bracket, the bracket needed a rear support.  I moved the idle air screw to the back and used the threaded idle air screw hole in the front of the intake manifold and made a small bracket to support the rear of the sedan AC bracket.  All that was as Joe Alexander described.
Tom Kizer