Originally the plan was to use Alfa Romeo 1.7 boxer 16v throttle bodies
However these are shaped at the bottom for the oval ports of the 16v Alfa head. They are also much more widely spaced than the type 4 head.
Instead 40mm Alfa romeo Spica throttle bodies will be used with the original Porsche 914 intake manifolds (these will need to be redrilled to match the 4 stud intake mount on the new head). The original manifolds will be cut horizontally, and a CNC cut flange will be welded to mount the throttle bodies to. The throttle bodies will need a Throttle pot added, but this shouldn't cause too many problems.
The throttle bodies have a 40mm butterfly, and are 40mm for 75% of the length bore, but are tapered to 36mm. Apparently this was because of the mechanical injection system - I will have these machined to 40mm for the whole length of the bore.
Apparently it is possible to open them up to 42mm, but you have to manufacture butterflies. For what I want the engine to do, I believe 40mm will be sufficient
Missing tooth removed from trigger wheel
Crank pulley attached to trigger wheel and hub