Q: What's that funky chord in Stacy's mom? The "not the girl for me" part  Is it like 3^7 -> 6min?
A: they are using distorted guitars, so in reality they will probably just play a lowish C in unison (song is in the key of E, for reference), but on paper as a song i would certainly say it's C° to C#min there. so in that sense making the C a 'power chord' would be rude, but not entirely a crime. they might have done it that way. or they might have fashioned it into a diminished chord actually, if only slightly. which can get kinda bloody on distorted guitars. anyway, i call it C° to C#min. and again for C#min the similar story applies, except for that one the 'power chord' status is not discouraged, it is helpful and likely. i'm just giving my professional opinion, i have not specifically consulted the audio for this question, although i am familiar with the song in general and have heard it several times before. And before i forget- to harken back to your original answer, yes absolutely correct, although again i would recommend putting the bass on C. which i'm 90% is what they did but as i said this is just from the way i remember it. Ok i'm going to stop being lazy and just go listen to it since i have already rambled on it for this long: ok yes, they have C in the bass, and F# in there also. which is the best all around compromise. executing the Cdim which as i said would be quite bloody on the distortion but that's the way it goes. it's always a challenge to make this kind of real harmony happen with distortion on (basically anything except 5ths and 4ths will make a mess) but yea, they did exactly what i would recommend. played it right down the middle, using C and F# notes to approximate Cdim in just enough detail to work properly while still keeping the sludge to a minimum