diff --git a/src/blocks/mrc_port.ts b/src/blocks/mrc_port.ts
index 2c355171..eeb2ad0f 100644
--- a/src/blocks/mrc_port.ts
+++ b/src/blocks/mrc_port.ts
@@ -25,6 +25,7 @@ import { Order } from 'blockly/python';
 import { MRC_STYLE_PORTS } from '../themes/styles'
 import { createFieldNonEditableText } from '../fields/FieldNonEditableText';
 import { ExtendedPythonGenerator } from '../editor/extended_python_generator';
+import { createFieldNumberDropdown } from '../fields/field_number_dropdown';
 
 export const BLOCK_NAME = 'mrc_port';
 export const OUTPUT_NAME = 'mrc_port';
@@ -99,7 +100,7 @@ const PORT = {
       const port = this.ports_[i];
       this.appendDummyInput('PORT_' + i)
         .appendField(createFieldNonEditableText(port.portType), 'TYPE_' + i)
-        .appendField(new Blockly.FieldTextInput(port.portNumber.toString()), 'PORT_NUM_' + i)
+        .appendField(createFieldDropdownForPortType(port.portType, port.portNumber), 'PORT_NUM_' + i)
         .setAlign(Blockly.inputs.Align.RIGHT);
     }
   },
@@ -156,10 +157,31 @@ export const pythonFromBlock = function (
   return [code, Order.ATOMIC];
 }
 
-export function createPort(portType : string) {
+function createFieldDropdownForPortType(portType: string, defaultVal: number): Blockly.Field {
+  switch (portType) {
+    case 'can':
+      return createFieldNumberDropdown(0, 4, defaultVal);
+    case 'smartio':
+      return createFieldNumberDropdown(0, 5, defaultVal);
+    case 'MotionCore port':
+      return createFieldNumberDropdown(1, 6, defaultVal);
+    case 'i2c':
+      return createFieldNumberDropdown(0, 1, defaultVal);
+    case 'usb in':
+      return createFieldNumberDropdown(0, 3, defaultVal);
+    case 'motor':
+      return createFieldNumberDropdown(1, 6, defaultVal);
+    case 'servo':
+      return createFieldNumberDropdown(1, 6, defaultVal);
+    default:
+      return createFieldNumberDropdown(0, 99, defaultVal);
+  }
+}
+
+export function createPort(portType: string) {
   // Based off of the port type, create the right number and type of ports
-  const ports : MrcPortType[] = [];
-  switch(portType){
+  const ports: MrcPortType[] = [];
+  switch (portType) {
     case 'CAN_PORT':
       ports.push({ portType: 'can', portNumber: 1 });
       break;
diff --git a/src/fields/field_number_dropdown.ts b/src/fields/field_number_dropdown.ts
new file mode 100644
index 00000000..1fe3bea1
--- /dev/null
+++ b/src/fields/field_number_dropdown.ts
@@ -0,0 +1,34 @@
+/**
+ * @license
+ * Copyright 2025 Porpoiseful LLC
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @fileoverview Create a field that has a dropdown with a number range
+ * @author alan@porpoiseful.com (Alan Smith)
+ */
+
+import * as Blockly from 'blockly/core';
+import { createFieldDropdown } from './FieldDropdown';
+
+export function createFieldNumberDropdown(min: number, max: number, defaultVal: number): Blockly.Field {
+  const items: string[] = [];
+  for (let i = min; i <= max; i++) {
+    items.push(i.toString());
+  }
+  const field = createFieldDropdown(items);
+  field.setValue(defaultVal.toString());
+  return field;
+}
\ No newline at end of file