I run around 32* advanced on my stroker, with a 670 cfm Holley.
Any bigger a carb and it floods ( on the street ) .
You might have to drop down on jet size's, or order up a set of 380 carbs.
I HATE 882 heads, I have tried running them and I didn't like them - swaped them out and cured a lot of my troubles, but a lot of people like them so I guess it's just a preferance.
Try to get it on the dyno- that will tell the tale of all your woes.