I would caution against taking harmala with more than at most 3.5 grams of mushrooms. I went as high as 4 grams with an unquantified small shot of harmala tea, and it was a wild ride... it actually was really nice and made the mushroom CEVs more closely resemble DMT CEV's, but then again it made the whole experience go in mostly unique way that I have never experienced before or since with either DMT (oral or otherwise) or mushrooms. That is until I inhaled a little piece of dead grass (Texas in the summer...) which made the trip awful and apparently that mixture makes me very emotionally fragile and my friends suggesting that it MAY just be a hallucination tipped me over the edge into a very painful emotional trip which resolved with an Identifying-with-Christ thing and ultimately helping my wife and I work on some issues we were having at the time.
So the mix is basically WILD and I would start with perhaps 2.5 grams (at most if you are experienced with mushrooms) and 3-4 grams harmala (depending on your tolerance to the negative side-effects of harmala, some prefer tea which doesn't really matter for me) or whatever dose of Caapi you find works for you...
and be careful, I've heard some terrible reports from the mix. I believe Terence McKenna said flatly "Do NOT do this!". So everyone is different, as with everything, all the time!