The 50cc accelerator pump on the 500 cfm Holley two barrels tends to be too much pump shot for a daily driver. On occaision, just switching the 50cc pump cam to the white 30cc pump cam can be the simple fix without addressing the rest of the accelerator pump hardware. A more extensive fix is switching the 50cc hardware to the 30cc diaphragm, cover, pump arm, and pump cam which is the complete fix. A smaller shooter size usually doesn’t clear up the problem as it’s the volume of fuel that is.
Overall, the 350 cfm two barrels are more driver friendly and also more fuel efficient.

Lorena, Texas (South of Waco)