Ford Racing has flowed a large quantity of injectors, and sorted and matched injectors with similar flow rates. These injectors are then packaged in sets. The end result is fuel injector sets with very small variations in flow. Typical production injectors can vary as much as 6 to 7 percent. These kits vary less than 1 percent, but typically vary less than .5 percent. The result is improved fuel control and optimized performance, driveability and economy. These injectors are attractively priced and cannot be duplicated for the price.