depending on which gauge I use (snap-on or mac) I'm either making 8 or 9.5 inches of vacuum at idle, and each read around 15 inches going down the road.
I've got the softest advance can I can find (B28, points style distributor, all in with 12 or 15 inches of manifold vacuum) so, actually The vac advance does kick in fully around 1500 or so rpm.
According to a wide-band display I'm usually right around 14.5:1 going down the high-way, so yes lean but not dangerously, almost ideal. some surging once in a while.
and yes, float height is set right at a .250" so I know it isn't caused by that, I adjusted it several times already, your float and accel pump are on the car, marked improvement in quality over stock units.