Hi I fitted new springs to my xj . i had to fit a 5in drop plate so i could tow my caravan . I don't know if you can drop the hight of a swan neck tow bar . BY the way my springs have not drop at all . my xj is still 5ins higher see pic in my postviewtopic.php?f=3&t=10032
There should be the bolt through the middle, and a metal clamp forward and rear of it to stop the leavestwisting along the bolt axis.