I connected the vacuum port to the nearest one on the carbs. The carb ports don't get as hot as the manifold ones and I didn't want the heat to deform the rubber mounting port because I've had a vacuum port cap on the manifold shrink up on me. I've got mine mounted using one of the chain guard bolt holes so it sits right behind the right peg hanger. The installation guide says that you should mount it as high as you can since it's a gravity feed system but I couldn't find anywhere else that worked well for me. I'll try to post some pics later.
