High float levels can affect idle, especially if the float is high enough to allow nozzle drip. Some of the later Q-jets seem to work better for me at a lower float level. They seem to handle greater than 6psi fuel pressures which is common also. It has been my experience that the pre-1976 Q-jet are more fuel pressure sensitive than the later models. Fiddling around with float level can make a big difference on starting, idling and overall performance, given the rest of the Q-jet is set up properly. It's all part of the joys of fine-tuning but the end result is worth it!
