I sure wouldn't pay $18. 00 for a fitting! There are two plugs in the intake manifold right behind the fuel filter near the MAP sensor. I forget the sizes (they're not the same), but both are common pipe-thread fittings and take a square-drive extension to remove. I went to Ace Hardware and found a reducer that takes one of them down to 1/8" (cost buck or two). Then I screwed in the 1/8" fitting that came with the boost gauge.