Another edelbrock carb question!
Too much secondary blade opening?
IIRC, you've had 3 carbs on this thing and they all act the same, ever think that it's not the carb?
Set initial CORRECTLY and it just might clear up the issue. Picking a number out of thin air IS NOT getting it done right, IMO.
The 360 had 16* initial and I thought it might be a little light, BUT, that was the limit of the tuning tools available. A likely lower compression 318 with the same cam, no idea if degreed, isn't going run at the same initial.
Good luck with it.