I have the Flex on my car.

I would recommend buying new wrenches from TEIN. The Flex coilovers are an expensive, higher end product, and ruining the "teeth" from not using the proper wrench would be a shame. For measuring the height, I took both shocks from the front of the vehicle and made sure they had the same measurments. I then installed the shocks, made even adjustments to the ride height (checked with a tape measure) and checked that the car was level. I put the drivers side shock 1/4" higher than the passengers, for optimal handling as when I'm driving fast I usually don't have a passenger. I think 1/8" inch would have been better. Repeated for the rear.

Florida