Setting the bar lengths equal is a good start, but the load on each bar from side to side with the car sitting on the ground can change things as Ken suggested. I've played around with this on my chassis scales with various cars, great setup tool for the street or any form of racing..... Another consideration would be the springs on the coilovers, perhaps one is weaker then the other. Also, you didn't mention, but do you have the adjustable Carrera's or the non-adjustable valving?????