The adjustment for 24# injectors in the Cobras was made in the ecu, not in the maf calibration. However, the transfer function in the Cobra meters IS NOT the same as the transfer function in the stock HO meters. Click on the link below and you'll see the difference. Use a Cobra meter with an HO ecu and you'll be lean in the higher flow ranges. If you simply want to plug one in and go, you'd be better off using the SN95 70mm maf. It's the same size as the Cobra, but the transfer function is a closer match to the HO function.
http://www.veryuseful.com/mustang/tech/engine/93cobra-maf-vs-stock-gt-maf.html