I don't believe that car will have the idle adjust knob. I think you have to go back to the pre-turbo models before they have one of those (W116?).

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k