Ok, '69 Camaro fresh 355, Comp Xtreme 274H flat-tappet straight-up, 1.5 alum rollers. 9.8:1, iron heads, 2.02" x 1.60", port-matched to Performer RPM intake. Pertronix billet flame-thrower distributor / wires / coil. AC-R44 plugs, .050 gaps, 12* initial, 35* total, vac advance (after setting timing) is hooked to timed port on primary metering block. Doug's 1-3/4" long-tube headers, AC mechanical fuel pump. On top is a brand-new QFT HotRod Series 680 vacuum secondary, out of the box stock. Vac power brakes hooked to rear (large) port, no PCV yet - just breathers on the covers. Both small vac ports down under the front fuel bowl are plugged. No vac ports on the intake.
By fresh, I mean break-in time (40 minutes) plus about 150 easy street miles. So, fresh. I've just got the electric choke / fast idle speed dialed in. Hot idle is 750-770 on my timing light, got it to about 10.5"-11.5" vacuum and all four corners just off of the rich side. If I open them each even a HAIR more, idle goes DOWN (rich). Point is, they are closer to the rich side than the lean side. Starts fine, idles great, haven't checked WOT quite yet. But, there's no indication it would be a problem. When it's running, the fuel is half-way across the fuel-bowl sight windows. So, floats are set.
Here's the deal you carb guru's: 1) Tip-in (idle transition) has a slight hesitation, like the accel pump is weak. There is squirt from the squirters IMMEDIATELY upon moving the throttle. I even lengthened the accel pump bolt (with spring) a few turns, but nothing changed. The hesitation is just a split-second and then it's clean and crisp. Cruise acceleration is immediate with no hesitation unless throttle is closed, then cracked open again for accel.
2) Overnight, the fuel bowls are EMPTY. No external leaks showing along the intake. WHERE CAN THE FUEL GO? Power valve(s) leaking and emptying the bowls into the motor??? What else is below fuel inlets (not draining back to the pump) that is open to the fuel in the fuel bowls?