sounds pretty dodgey to me,

id say there would be a better way to do it, are you using a stock manifold and carby?

it should recieve signal from all four pistons

actually i think i know what you are using, there is a fitting with a big tube for the brake booster and a small for vacuum advance, both from te number 4 inlet

i am using the brake booster one but not the vacuum one, id like to plug that and use another outlet on the manifold for the booster (before the seperation to each piston, there is outlet on the passenger side just below where the carb bolts down)

but at the moment as i have a 32/36 weber, it has an outlet for the vacuum advance on the bottom of it and i am using that for the advance