The number for my celica engine is V0071893, and the manufacturing date on the driverside door was 02/07, so I would say that it would be an accurate guess to say the last for digits are what # your Celica was in the limited cycle. Dunno as for the # would have been seperate for the ST's and GT's, and I have no clue about the GT-4's as I don't know much about them. Check the sticker on the driverside door and look at the date if you are questioning the date your car was made.