A lot of us install a Vacuum block/ Vac manifold on the brake booster line and all of our vac off that better more secure site. The nice thing about it is that your not all T'd in to other lines like how Mazda did it. If you have a leeak it will be much easier to source, and everything (gauges and SSAFC ect) will all be seeing the same vac and boost. So its more consistant