Greg Biffle capitalized on Jimmie Johnson's misfourtune on Sunday to win the Michigan 400 at Michigan International Speedway.  Johnson held the lead with less than 10 laps to go but blew his engine and finished 27th.  Biffle passed second-place runner Brad Keselowski for position just prior to Johnson's mishap.  Johnson's engine troubles led to a caution and setup a green-white-checkered finish.  Biffle held off Keselowski for his third win at MIS.  Kasey Kahne finished third followed by his Hendrick Motorsports teammate, Dale Earnhardt Jr., who won at Michigan earlier this year.  Marcos Ambrose, who won last weekend's road-course race at Watkins Glen completed the top-five.