The Cobra motor was equiped with 24lb injectors from the factory. The Cobra computer was tuned to take this into account, and did not use a mass air meter calibrated for 24lb injectors, like most of us do in the aftermarket. Like stated above, if you use your factory 19lb injectors, you will be fine. If you use the Cobra 24lb injectors, you will need to buy a mas air meter which is properly calibrated for the 24lb injectors. This is really the only difference. If you really don't want to spend the money on the mass air meter, the 19lb injectors should be suffecient to support a stock Cobra motor.
Joe