I have had 3 boats with topping lifts attached from the top of the mast to the end of the boom. On the end of the boom I have a swivel block. The line runs through the block to a cleat, forward and on the side of the boom with a hole in the middle. Thread the line through the hole in the cleat and secure with a figure 8 knot, leave enough line so that when you uncleat it you will clear the back of the sail. this is a good flexible setup and it costs a heck of a lot less than a ridged vang. You should also have an adjustable vang for this type of setup. Ray