Instructions not great, but if you have some fabricating experience youll make do. One issue that shouldve been a duh is that the rivets supplied are all flush, which is fine, but the supplied nutplates are not countersunk to accept the dimple that needs to be accomplished for a flush mounting surface. Can get by in a pinch with some modified dimple die and a squeezer. I decided to shift the collar upward such that the actuating flap was allowed a greater travel for more airflow. Then I laid a fillet of high temp silicone against the gap created by the shift. An improvement to the design/kit would be to have the actuating arm mounted on the forward side of the flap so that a second collar assembly could be mounted inside the cabin to distribute airflow as desired. All-in-all, not a bad solution for a budget. Can be modified to your purposes easily.