Like i said before...i have done the same exact way you do now....like 15 years ago.
What is important....the airbox above your injectors has to have the same cc as your engine....this means that the airvolume above the injectors has to be around the 2500cc.
Then i to had my injectors on the same spot as yours and have noticed that they spray against the inside wall off the adapter.....so the fuel leaks/ runs down to the valve
So i tried all the things you are doing now with this setup and mine did run also...BUT.... or it ran stationary fine but when reving it didnt got enough feul......or i adjusted is so it could run when reving the engine but verry rich when running stationary.
Solution....Make a bigger airbox above the injectors .
Put the injectors just in front of the intake valves. ( i had mine drilled in the original intakemanefolds )
You are 9n the right way and you will figure this out....yust keep on testing
Build projects, things that guys have come up with to make a Pinz better (or worse?) and aftermarket add-ons.