Ok, well Ive finally driven my recently 16v converted ae86. It all runs sweet, except that the brakes feel unusually hard.
They seem to stop ok, but just require more pressure.

I have swapped from a 4age 20v with open trumpets to a 16v with the same itbs and trumpets on it.
The only thing I have changed is that now I have an aluminium manifold hooked up to the stock 20v vacuum ports, which then connects to the map sensor and the brake master.
The vacuum ports from the T3 manifold join together and connect to the FPR.

Also, the 16v has ~290 degree cams, would this affect the vacuum at low revs causing the brake to be hard?