I am looking for an ECU unit for my 2003 GTX 4-Tec Supercharged. The dealer (who wants $740 for one) tells me that the part number is 420-664-566. If anyone has one, you can email me directly (gonufer@sbcglobal.net) or call me (949)521-0407. Hopefully save me some money and put some in your pocket too.