I see now. Here is a oem picture if you need one.
Search 99611021571 - 99611021571 - Turbo Intake Plenum - ES#1483665
Crazy there is no 74mm option for you besides the IPD piece.
Maybe you could have someone with a 3D printer do one for you. There is a member on the forums here doing some 3D printed plenums to get a 74mm tb on the Boxster and keeping it pretty close to the factory location.
http://986forum.com/forums/diy-project-guides/55966-intake-plenum-911-throttle-body.html