Almost forgot...
Since I'm in there anyway, I ordered a 997 plenum and some new plenum boots to go with the 74mm 996 throttle body I ordered. Once the IPD intake tube arrives and I get everything back together, I'll also have a bigger intake to go with the new exhaust.
I simply can't justify the IPD plenum at (literally) 10x the cost of a 997 plenum. The 997 plenum is also 74mm to go with the beefy throttle body; it just doesn't have the sexy aluminum body and the machining inside. I'm sure IPD's stuff is crazy good and superior to a stock 997 plenum but I figure that 1) it's bigger volume than what my 3.2 came with, and 2) at 10% of the cost of an IPD plenum, the 997 unit will be "good enough."