Did you check the Q jet for straightness, sounds like the throttle body or Float bowl is warped?
Primary Shaft leaking? loose, All easily fixed.
No you do not need an adapter, I am also going through this too, mine was warped and lots of leaks. I had to unwarp it then find and correct any mistakes I had made.
I found I had set the throttle plates off, shafts were binding plates not closing.
You also need to choke her til it gets up to temp.

I was told by the Carb Shop in MO to trash the Edelbrock Performer Manifold and use a 1968 Q jet stock cast manifold, I have since removed the Eddy.
Now I am learning how to setup and get the Q jet right for my setup and I understand that I will never go back to a Carter/Edelbrock once I get it right, I am so close.