So I noticed that when I installed my Pitster pro 140 on my ATC 70 that I had a spacer with no O ring slot in it and one that did have one. I was just wondering if the spacer with the o ring is supposed to go on the head side or the carb side and what is the proper orientation to install them such as facing the carb or facing the intake. I have to stock carb that came with the 140 and the piranha intake. I also have a spacer between the head and the intake and the carb and the intake. The O ring provisioned one is currently on the carb side.Thanks.