All of our sets are flow-matched to 3-5% of each other during our standard remanufacturing process, but this does not come with documentation. We offer advanced flow matching which does include documentation. The closer that the injectors flow to one another, the more precise the entire fuel system will be which makes it more efficient. This improved efficiency manifests as better fuel mileage and a smoother engine.
As far as which option is correct, the choice is entirely up to the customer based on their individual needs and budget. Please send us a message BEFORE YOU ORDER if you would like to upgrade to an advanced flow-match.