Keihin vb32 vacuum piston

I have a 1978 kz400 b1. I have a problem with the vacuum slide. I removed my diaphrams because they were torn. I needed to know which side the two holes are suppose to go towards when i reinstall, engine side or air filter side? Of coarse i forgot to look before i took it apart. The diaphrams origanally had a notch in them so i know the are suppose to only go one way. Any help would be greatly appreciated. Also was wondering if there is a difference between vb32 carbs and Cv32 carbs?

I found the answer to this question if anyone needs to know. Holes go toward the air filter side.