The link at the top is clearer on some of that stuff.
Every combo needs diff. amounts of air...boost and N/A also play a large role in how much air is put into the motor.
I just wanted to make a list of mafs how much they flow (and with a maftransfer if possible) and what people have gotten with mafs that flow x amount. More for ref. to see what people can get from what mafs.
Also notice that 4.6-4.7or so on the trasnfer is more like the "safe" or at least "safer" limit you should look at. If your hitting the 4.8-5.0 range your prob. peggin the maf or at least getting really close and should look for one that has alittle more flow room.
For instance I noticed that my maf was getting alittle on the higher side of the transfer volts. That is why I was looking into diff. mafs. I dont think the Lmaf would be a good fit for me as I simply would not use the full maftransfer and simply not needed. Then I noticed the 98gt mafs flow was a nice medium with more headroom than the stock 94-95 meter but not as much as the 90mm Lmaf.
In short IMHO its more like match the maf to your combo's needs, if you dont need the flow why spend the money on a way bigger maf than you need. Esp. if you can find a factory smaller one that meets your needs better and will prob. be cheaper as there is no reall demand for said "other" meter.
The newer mafs on the modular mustangs and lightnings will need a new maf plug or pigtail harness as they use a "new" style plug. Another thing is the way the airfilter mounts to the newer mafs, you will need an adaptor of some kind. I had a old K&N filter that had a plate that mounted to my stock maf that I re-drilled new holes to match the 98 meter, and cut the hole bigger to match the meter.