Found a minor misalignment in the choke linkage that prevented air valve lockout from releasing. Shortened choke linkage a little and air valve now opens easily manually with engine off. In the garage, the air valve doesn't open but maybe I'm not revving the engine hard enough to open the secondaries. I will try to road test tomorrow. I tested for vacuum leaks but didn't find any.

Acceleration does not improve with engine rpm, but comments about possible first gear slipping are interesting. My Dodge truck has an engineering problem that causes a very dangerous lack of acceleration problem when cold. Pulling out of my driveway onto the major road, especially in cold weather, is dangerous as the engine revs and the torque converter slips. The 'bird doesn't have that feeling, and trans fluid is clear and bright and fresh smelling. Instead, the engine just doesn't have any real acceleration from a standstill or low speed start. It doesn't overrev, it just doesn't open up quickly.

I will change the springs on the distributor tomorrow after work if I have a chance.