Several years ago I bought a plenum from phrogs that was missing the MAP sensor ears. I Siamesed that the Inj housings and the heads....with small intake cams(222 .415 primary/236.425 secondary) I made 441RWHP/7100RPM; that's untuned.
Since then I ported the inside of the plenum removing all of the water passages and guts(There are significant blockages to the #1 and # 2 intake ports, etc. Added a 63MM TB.....
I decided that now I am going to add volume to the plenum; I will be cutting off the roof unshrouding the runners adding an inch, and cutting the bottom off and doing the same.
I am also going to do some air intake testing.....I know people say there is nothing there, but I want to try a few ideas.
Here is where I started with the Siamese