I wanted to reuse the original airbox and filter, as well as reinstall the original MAF and intake air sensors for later data acquisition (and to avoid throwing codes!).
Luckily, the airbox is on the same side as the intake manifold, so the design is greatly simplified. I used a 3" to 2" reducing 45-degree elbow, a tee-fitting with a 1" port for the temperature sensor, and a 90-degeree elbow to the engine, all connected with short lengths of 2" OD Steel pipe.
The hardest part was the intake manifold adapter, which has an oval inlet. I machined the oval port on a piece of 1/8" steel plate, formed one end of a 2" steel pipe into a matching oval, welded the two together, and trimmed everything to fit under the hood.
