[DanEC]

I see 16 inches in the 427 manual for the trailing arms. A couple of us ran into a little interference between the tire and the front of the wheel well and Doug advised extending the trailing arm link a little to swing the suspension assembly rearward slightly more, providing more clearance. I don't think a precise dimension for the trailing arm adjustment is critical to anything as long as the suspensions and tires cycle without issue and it's equal on both sides. But a quick call to Doug should get you an answer.