Aeroflow Flex Fuel/E85 Content Sensor Bypass Block (AF64-1555)E85 CONTENT SENSOR BYPASS Black Finish, 10ORB Ports Part Number: AF64 1555 Aeroflow Performance flex fuel E85 content sensor bypassblock is designed to be used with our E85 Content Sensor (AF49 1555) or ACDelco (GM) 13577429, 13507129. This blockhas been engineered with a dual flow system to provide optimal flow without restriction when using this sensor on either the feed or the return. This block has an integral bracket for mounting on a frame rail,