[rotrex]

Less flow would let it run richer. It is more common with side fed manifolds that have a uniform cross section that the first cylinder closest to the inlet runs leaner as it gets more air. Airspeed drops for the others decreasing flow. The more boost you run the worst it gets. Dedicated FI manifolds gradually narrow down in direction of the last cylinder to maintain airspeed despite the cylinders ahead already getting air. An other way is a primary tapered plenum feeding a secondary plenum chamber through a full length slit. This feeds all cylinders equally.
The jet position looks ok. Closer to head seems difficult the achieve as there is no space.

Just run a 50:50 mix to start with. It will be amazing.