Several things to note about the pipe that may not be obvious from the photos:
1. There is a bubble flare on the short end, where the flexible hose to the air filter shroud connects. The bubble flare has an OD of apx. 2.67", and the centerline of the bubble is apx. 0.313" (5/16) from the end of the tube. I say approximate because this pipe is not a precision piece of manufacturing, and the end of the pipe is not cut exactly square.
2. The short curved end of the pipe is not parallel to the mounting flats on the two "L" brackets. Instead, the short end is rotated 10deg from the flats. See the "End View" in the drawing below.
3. The "L" brackets are welded to the intake pipe along their sides only.
4. The pre-formed length of the "L" brackets is about 5-3/8"
5. The mounting holes in the "L" brackets are 0.405" in diameter, and are 5/8" from the outside edge of the bracket flat.
6. The mounting bracket flats are bent 90deg from the longer side that is then curved to fit the OD of the pipe.
7. The mounting flat of the "L" brackets is 1.62" in width (the long axis of the pipe), 1.44" in length (measured on the underside, see photo No. 5 below).
8. The distance from the mounting bracket flat underside to the outside of the pipe is 0.64"
9. The thickness of the stock used to make the brackets is 0.19"
10. The pipe wall thickness is 0.050"