One more piece to your puzzle. This entry from this online parts service shows a transmission with your part number and the DXF designation being for use with the 4.3 L engine and used in a 2007 year. You'll know more after you chat to a good parts dealer. Again good luck. https://www.wholesalegmpartsonline....assembly=372049&ukey_product=2667325


"Nothing astonishes men so much as common sense and plain dealing." - Ralph Waldo Emerson