I've set the timing on my '81 350 at zero, as recommended, rebuilt my carb and at WOT, my '86 is running pretty damn strong. Unfortunately, when I stay out of the four-barrel (CC Q-Jet), the engine seems to lurch a bit and just generally runs a bit unevenly.

Could it have something to do with the tampering with the set-screw that occurred when I adjusted the A/V? Any other suggestions? I just replaced the TPS as well.

 

Sounds like the primaries are too lean... nothing you can do to the secondaries, or have already done like the AV, will affect that.

Try adjusting the idle air bleed valve in, in about ¼ turn increments, see if that has any effect.