AMS EVO X Adjustable Fuel Pressure Regulator Kit In Black 25-90 PSI 6AN 4B11T. Please message us for a Return Authorization Number before sending anything back to avoid processing delays. Real Street Performance is unlike most “Race Shops”. We are a fully functioning wholesale and retail distribution warehouse in addition to a dyno-equipped tuning and engine building facility. Our sales center and order fulfillment center operates with state of the art, industry leading software that allows us to get you ALL of the parts you need for your build quickly and correctly the first time without the headaches or excuses. Sign up to our Newsletter.