This is a 6 bolt to transmission-6 bolt to transfer case adapter. The last 3 numbers of the casting number end in #744. The casting number is located on top of the adapter and is hard to read unless you remove the adapter. This extension housing is usually found on the transmissions that fit the 5.3 engine in most chevy trucks from 1999 up. It measures from flat to flat aproximately 4 1/2 inches.

THIS ADAPTER COMES WITH A NEW GASKET AND A NEW O-RING TO ATTACH THE ADAPTER TO YOUR TRANSMISSION AND TRANSFER CASE.