Edit: still curious on what your plans are with the emb and quads are adam!
The 4AG quads fit the bore spacing of the NA6 perfectly. The AE101 4AG (Silvertop) injectors are only 30cc larger than the stock NA6 ones. The factory manifold has vacuum, fuel etc in it already.
Once I have this engine running, my next project is to build a manifold to adapt the quads to the head. Think two flanges with
very short connecting pipes. There was a mob in Thailand or Malaysia making a billet adapter, but I cannot find details for them anymore.
Then I build an atmosphere-side plenum for the quads to draw their air from.
Then I connect the whole lot and install it.
It could take me a year or so to get that far....I have other hobbies that draw on my time and money.
The EMB will tune the quads adequately if I install a true TPS (which the quads have on them already). Since I intend to keep the AFM upstream of the plenum, the original engine sensors will remain.