How can I change a grid to use NADCON for NAD27 to NAD83 translation ?

By default, all State Plane grids that use NAD27, use a regular (Molodensky) NAD27 to NAD 83 transformation.
It is not very difficult to change the built in grid to use NADCON conversion:

• Make sure you run the software as an Administrator, or make sure UAC in windows is turned off;
• Select the "Manage Map Grids..." option from "Options" => "Coordinate Systems" in the main menu;
• Select the grid you want to change and click the "Modify" button;
• Locate the datum field (which should state "NAD27") and click the "Select..." button next to this field;
• In the "Select Datum" screen, select the "NAD27 (NADCON) option, or one of the other NAD27 (NADCON) variants, and click "OK";
• Click the "Save" button;
• Repeat this for each grid you want to change.

Select the "Manage Map Grids..." option from "Options" => "Coordinate Systems" in the main menu

Select the grid you want to change and click the "Modify" button

In the "Select Datum" screen, select the "NAD27 (NADCON) option,
or one of the other NAD27 (NADCON) variants, and click "OK"