Easy questions: Is the diff ratio on the VS Calais with the super 6 or V8 any different to the ecotec? Are the transmission ratios any different?
GU4 is the standard axle = 3.08:1 open wheeler ratio unless it's been optioned or swapped to something else... Dont know about the trans...I've heard they have a heavier duty torque convertor... and maybe the shift points are revised.