[The Radium King]

the tune from a 2004 spyder will only work on a 2002- car (7.8 dme). I was able to get the airbox in without denting anything (you do have to modify the airbox by removing the muffler, and getting it in is a bear but very possible with engine in place).

from what i recall the 987 MAF housing ID is 83mm not 90mm (vs the 986 76mm) but yes, reusing the oem maf housing does keep one restriction in the system but is necessary unless you retune your car - oem tunes can be used (5 mins with your indy and a pst2/piwis):

2002- use the spyder tune
-2000 use a 2000, 2001 996 C2 3.4L e-gas tune (the 1999 was cable throttle)
5.2 dme cars? dunno. cable throttle cars? dunno.

while keeping the restriction in the system isn't the perfect solution, you still see benefits as can be attested to by most who have done the work. compared side by side, there is no argument that the 987 airbox can move more air than the 986. the other thing to realise is that this is a change to the overall principle of operation of the intake - from a reducing diameter system designed to accelerate the air into the cylinders and facilitate induction at low rpms, to an unrestricted system designed to move a lot of air at higher rpms - in this context reusing the oem maf housing is not that bad a compromise, although I could understand in jsceash's situation the 3.6 might suffer more from the restriction than a 2.7/3.2 car.