I have the TH2004R out of a 305 (H code LG4) 1986 Grand Prix and am wondering what the stock rear axle gearing was for that car? 2.56? 2.73? I have a 3.23 axle from a 83 Regal in my car and I am trying to figure out what drive gear is on the output shaft of the trans so I can get the right driven gear to make the speedo read properly. Thanks!