Sound to me the accelerator pump discharge nozzle is too small or not working. Holley sell different size nozzles if the one you have is squirting. The specs sheet states you have a .028 I would try about a .032 to see if it improve. Here is a list of what Summit Racing has to offer:
https://www.summitracing.com/search/...rder=Ascending
Here is a list of specs for the 4412 (among other carbs.) showing what size nozzle and other spec that came with you carb:
http://documents.holley.com/techlibr...al_listing.pdf
Here is some tuning tips from Holley:
http://documents.holley.com/199r7950-7rev7.pdf
Here is some accelerator pump tuning instructions:
http://www.racingjunk.com/news/2015/...elerator-pump/
I hope this will help and not be information overload.