What maf (year, make and model) do you have and what (maf) do you wanna use?

Most of the maf's for Ford, or aftermarket maf's, are calibrated for certain injector size and certain computer. C&L and Pro M are probably the most popular aftermarket maf's. If you want to stay within the Ford family of maf's, then you will need to check injector size, computer and flow chart for what you have and compare it to what you are looking at installing.

Some guys are putting on Lightening maf's on their Mustangs, but they have to either get a chip or get their computer retuned for the different air flow and voltages of that maf.

Here is some good discussion on the Lightening maf's

http://www.corral.net/forums/showthr...highlight=24lb