Center to center, the actual distance from the center of one bushing to the center of the other bushing. I realize they have been the same length for many years, but that in it self does not give me the length! I need it to build a jig for welding. Measuring the bolt ends while the arms arm in the car is not accurate enough because of the deflection in the rubber. I do not have any arms other than the ones in the car and did not want to remove one just to get the measurement for my little project. This is why I asked if some one had the design length not a tape length. Thanks.