On this engine we used ITBs with 2 injectors/cylinder. For vacuum we made a small manifild that sits on top on of the breather tower on the engine case. This manifold accepts a vacuum hose from each barrel (6) and has a port for the power brake hose.
Typically you are only braking when off throttle, butterflies closed, therefore high manifold vacuum for the brake booster
If you look closely at the pic under the FPR you can just see the manifold and brake booster hose connection. I never took a pic of the manifold seperately
