I always liked my avs.A mechanic friend who was(he's passed on ) much better with carbs than me, set mine up for me when i was running a standard. The secondaries opened kinda late,giving time to build vaccum and made my 327 seem much bigger than it was.(My theroy) I now have the performer on the truck and taken for a test drive. Seems to have a little flat spot, but i can probably tune it out. Carb King, what do you suggest, timed vac, or manifold vac for my dist. advance. I have always run timed.