well, the 2g maf reads up to 2800+hz, it's hard to imagine anyone would need more than that, and if they did they'd be at the point where a standalone would be used...another bad thing would be actually finding room for two MAFs, they're pretty bulky.
i don't believe i have ever seen dual MAFs on a car that was originally designed with one...i'm inclined to say it can't be done without ecu reprogramming...
sorry i didn't answer your question, but at least it'll get bumped back up
marshall