If its a stock meter the car needs a chip burned to compensate for a larger injector or an aftermarket meter that is calibrated to the injector. They are calibrated either by a flow tube or an electronic fix. I have never heard of just buying the sensor as they are matched up to the housing in some respect, I am no expert on this topic but would be interested if indeed, you can buy just the sensor.
C & L makes MAF sensors that use calibrated flow tubes, as opposed to electronic sensors. You actully just remove the sensor and plug from your factory MAF, and install it on the C & L. They, along with Vortec, are a one of the only companies who use the calibrated flow tubes. Companies like Granatelli, and Ford for that matter, use re-calibrated sensors.
You won't be able to use a Ford product, if the sensor was not calibrated for 30 lb injectors.
is the meter squared off on one end and you had to use an adapter for it? if so then it's a 94/95 meter. if not, then it sounds like you have the same "93 cobra meter calibrated for 19# injectors" i had for a bit. regardless, if you want to keep that meter, you'll have to take your car to a tuner who can adjust and compensate for the larger injectors in the ecu and burn a chip for you. this can cost upwards of $300 depending on where you go. compensating for the larger squirters by adjusting the a/f tables in the ecu is the proper way to do it. of course the other option (and most common) is to just buy a whole new meter calibrated for whatever size injectors you have. doing it this way "tricks" the ecu into thinking more or less air is entering the engine. both routes have their pro's and con's, do whatever is in your budget. if you decide to just get a new meter, you can get one almost anywhere that sells stang parts. summitracing.com, jegs.com, latemodelrestoration.com, cjponyparts.com, etc. unless you have a stock airbox, i suggest you stay away from C&L's meters. a lot of people have had idle issues with their meters, even with stock airboxes, including me. on the flip side, most will point you towards Pro-M meters. tried and true, very good meters. i have one on mine car and have not had a single issue with it. either way you decide, good luck and hope this helps some!