Lean out and miss fire
We need to know more.
Engine build (Heads, cam, compression, intake, etc):
Carburetor brand, size and any changes from out of the box:
Initial and total timing:
Fuel System (i.e. what pump, line pressure)
Distributor part number and what ignition system (i.e Stock, MSD, etc)
Condition issue occurs (Cold engine, just after its warms up, etc)