Using gii, I created a model based on a database table and then CRUD for the model. One of the columns is showing either 1 or 2 as they are stored in the database. To create new, it was easy using a ActiveForm->dropDownList() widget:
<?= $form->field($model, 'type')->dropDownList(['1'=>'Role', '2'=>'Permission'], ['prompt'=>'Select Auth Item Type']) ?>
How to use GridView and show Role instead of 1 and Permission instead 2?