Ford made a limited number of the Mustang Cobras with a “super-high-output” 5.0L in ’93, ’94 and ’95. They all had a unique roller cam (p/n F3ZZ-6250-A) that can be identified by the “GT” stamped on the barrel, right behind the distributor gear. This cam was designed to work with the specific combination of heads, intake, throttle body and injectors found on the Cobra engine, so it had different centerlines (115/121.5 for the Cobra vs. 116/115 for the H.O.), less overlap and slightly more lift.
This profile produced a smooth, stable idle, reduced hydrocarbon emissions, and gave the Cobra more low-end torque at the expense of some top end power. This cam was also used in some late ’93 5.0L Thunderbirds to “improve idle stability and reduce hydrocarbon emissions.”
Engine builders should throw this cam away unless they’re building a genuine Cobra engine. It doesn’t do a good job in the Mustang 5.0L because it doesn’t have the right profile for this combination, so it affects driveability and gives away some horsepower, too. It can also create problems if it’s used in any other 5.0L application except the 1993 Thunderbird that came with the unique, restrictive intake that was required to make the 302 fit under the hood of the Thunderbird.