Rob is correct & should have worded differently. The AVS secondaries are mechanical and it is the air door adjustment that controls airflow to secondaries that helps control/eliminate a bog. Love the ease and simpleness of this adjustment. The 670 avenger is an awesome carb from my experience and is vacuum secondary, but has a neat quick adjustment setup with just spring changes. I could just not get an initial bog out of mine but it was my limited holley tuning ability not the carb. Only reason I really changed from the avenger was my comfort level tuning eddy's and mine developed a leak over the winter down period( probably from sitting ) so would absolutely recommend the avenger and am thinking about trying the 570 cfm unit on the 273 in my valiant.
Oldschoolcuda
