I glass-bead the surfaces with ultra-fine beads and low pressure; THEN send the zinc alloy casting to a metal laundry company to re re-chromated.

All zinc-alloy carburetors will have this problem, Carter and Rochester seem to have it more so than Holley, Stromberg, or Zenith.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop