Another possible cause of the bog: your secondary opening rate is controlled by a vacuum diaphragm. Holley makes an inexpensive kit with different spring tension choices - a stronger spring may fix that by delaying secondary opening until engine demand is higher.
http://tinyurl.com/y8thdk2a.048 to .052 isn't 4 sizes, it's 12.5:1 instead of 14.7:1 cruising mixture, and when combined with your .038" PVCR it's 10% richer WOT (13.0:1 becomes 11.7:1 A/F).
