check the option codes. should be in the glove box or in the center console. its a sticker with a mess of letter and number codes. should be a gu4, gu5 or gu6. that will tell u what was it the car when it came out of the factory, now to tell whats really in there u will need to jack up the rear of the car and turn the wheel one revolution while u count the number of time the driveshaft turns. if it turns a little over three times (3 and 1/4) its a 323, if it turns about 3 and a half times its a 342, if it turns almost 4 times (3 and 3/4) its a 373, if it turns a little over 4 u have 411

 

manuals came with 3:42 from the factory