Have a 3" MAF housing made, then rescale your MAF to suit the new housing. You should be able to run in the 15-18psi range out of the stock MAF with a 3" housing without pegging the sensor.
An alternative is to try an Impreza MAF, which another member claims is plug and play. I would recommend rescaling your MAF with this too however, but the thread is here:
http://www.ft86club.com/forums/showthread.php?t=106496
Last option is to run speed density if you are on EcuTek. Running full time speed density will allow you to remove the MAF altogether, if you use a separate intake temp sensor.