I have the part # for the MAF housing at home if you need it. It will only be $7 from your Ford dealer. I cracked the filter flange on mine from overtightening, but I think I may have weakened or cracked it when I was forcing the tight "hump" hose onto the housing.
Was the crack through the flange that the filter attaches to, or through the center of the housing? If it was through the center of the housing, I would blame that fact that the hole in the heat shield isn't centered properly for the MAF housing, and the housing makes constant contact with it. This is an issue that K&N is aware of, but I have no reason to believe it's been fixed yet. I have modified mine to eliminate that problem.
I mentioned this in the K&N CAI thread, but I will mention it again. It is very important that you don't overtighten the filter to the MAF housing. Tighten the clamp until the filter no longer "slips" on the housing as you try to rotate it, then turn the screw on the clamp just a bit more.
Mk3 |╠╬╝|SGM|203a|Moonroof|17" Paint/Mach Whls|K&N 57S-4000 -snorkel|FFE RMM|Steeda STB, RSB|JBR bushings
Mk1|╠╬╝|Pitch Blk|Prem pkg|Moonroof|SVT Snorkel|SVT Susp|Steeda STS|Z-Eng RMM|Magnaflow exh