That is a design change; although, it was done some years ago and is shown in the Bentley manual directions. That threaded barrel at the end is there to compensate for any differences between the block mounted lower timing case and the head mounted upper timing case. Just torque the lower 3 bolts that hold the guide on and then adjust the barrel so that it just seats on the upper timing case. Then insert the bolt and torque it down. Loctite if you have any available, but not required AFAIK.