This is a messy setup to get right ... in fact you never will :( I did a similar thing with a turbo on an L20B blowing through a 48mm side draft dellorto.
You may want to put a fuel pressure guage in so that you can check that the fuel pressure is always more than the boost pressure. If not, the greater pressure in the carb will prevent fuel from entering. I used a second hand injected volvo pump.
Next problem is mixtures. Injection systems can tolerate small changes in air densities and change mixtures to suit - carbs can't. You are pushing high density air into the engine so you will need more fuel. The carb will only add more fuel if the volume of air passing through it increases. It will not measure the air density.
You will need to rejet (drill jets?) your carb to suit. Best way to do this is with an exhaust gas analyser to check mixtures under a variety of driving conditions.

Good luck.