Carter/Eddie AFB question

I was messing with my Swinger the other day and decided to slap a 1406 Eddie on it just to see how it performed with a tiny carb . (This is a 408 with W2s , solid roller and Victor single plane intake . ) I set the floats , idle screws and transition slot then instaled it …. Wouldn’t idle unless I opened the idle screws 4+ turns and cranked the throttle screw a few turns .
Hmmm…???
So I grabbed a Carter Competition 750 off the shelf and repeated the process .
Same outcome ! I double checked for vacuum leaks

What simple thing am I missing ?
Ran fine with my Pro Systems 850 on it ….