For the 42.5 pound Lucas and 60.0 pound Siemens injectors, it's not worth the extra money to have them flow-matched in our opinion. In almost all cases, they are nearly perfectly matched already - straight out of the box.
The 50.0 pound Delphi injectors are a completely different story, in that their consistency is MUCH worse. We won't even sell or install those in an engine without them being flow-matched.
They're all flowed and then grouped together in 'matched sets'. So if a hundred injectors get flowed, and six of them flow between 46.2 and 46.4 pounds per hour, then those six are good enough to be bagged together and sold as a 'flow-matched set'.
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