74? go for 82.
before you go IPD, take a look at Ben's solution.
i have one of his 3D printed prototypes installed on my 996, and absolutly loves it.
http://986forum.com/forums/diy-project-guides/55966-intake-plenum-911-throttle-body.html
cant wait to get my dirty fingers on that new and shiny CF plenum. :dance: