Thanks for the replys.

There's a good steady manifold pressure, the ITBs came with a vacuum manifold and built in restrictor. Standard cam.

I got the ignition setup and working before swapping the head and injection on so at least it's only trouble shooting one thing at a time.

It's looking like I'll have to build a jig to measure the flow. Knowing the injection parameters will make it much easier to get a base tune and also allow me to get the VE map right.