I would try it at 5 psi for sure that can be the problem if its flooding over the floats. Not all carbs and fuel pressure regulators will work correctly at max pressure. Best to pull it back some i bet that will help smooth things out a bit.
If it solves the problem but runs lean at wot the regulator needs to be upgraded. Tbi pump should be fine but regulators usaly cost a pretty penny for a good one.