AFR's & fuel pressure are solid. Pulls like a train. From what I was told, the 740's are underrated and the SARD 850's are overrated. I was told they flow about the same. I have no experience with 850's. I am running the equivalent to about e75-e80. The higher the content of ethanol the more injector/fuel you will need. As for me I'm getting by just fine on the local juice.