1966 Dodge Dart GT Factory Ride height?

mopowers, thanks for the info on the front suspension. I'll certainly use it when I get that far.

My questions are with the rear suspension ride height. My old method of measurement was to measure the height from the florr to the bottom of the rear wheel arch in line with the wheel hub. I just got the '64 Dart GT and it looks like it's down by the a$$ a little. Measurements at centerline fender well with 3/4-full fuel, empty trunk, and 185 75R/13 tires are (L) 19 1/8", (R) 19 5/16". 184K with 95% driver-only use (one owner).

What is the spec for rear ride height and how is it measured?