Thanks for the above. I should have stated my problem more fully. I suspect that my current rear box mounts have sagged some - the gearchange mount seems lower than it should be, and the radiator fan runs close to the shroud at the top, and is definitely not parallel to the core -although that may be normal, but...The engine has a distinct incline to the rear. All this means I doubt that I have a reference for where the drive flange should be height wise. If I knew where it should be relative to the tunnel above I would have some idea how much the mounts have sagged, and if I should do them before I get the LT77 ready to go in. Havent had mine over 50mph/80kph yet, no vibration apparent so far. I have an auto prop shaft ready to go in with the LT77, and it took some cleaning and careful examination to locate the alignment arrows, and they do line up well now, although they werent a;ligned when I got it. IIRC the WSM specifies two different alignments of the UJs?