Go by the factory service manual numbers.
From the 1996 manual:
The measured FRONT height "spec" (Dimension P on the illustration), through the centerline of the wheel hub of a 9C1 (RPO 7B3 suspension), from the edge of the wheel opening vertically down to the surface the wheel/tire is resting on, regardless of OE tire size, is 28.6" or 726mm.
Stock tire sizes with 7B3 vehicles were 215-75, 225-70, and 235-70 R15.
The same measurement for an Impala SS/WX3 (RPO FE4 suspension) is 27.8" or 706mm.
Stock tire size with FE4 was 255-50 ZR17.
The measured REAR height spec (Dimension R) measured vertically through the centerline of the wheel hub of a 9C1/7B3 vehicle is 28.8" or 732mm.
For the WX3/FE4 rear, at wheel opening, the measurement is 27.3" or 693mm.
You have to remember that the manual specifies:
taking measurements on a validated flat surface
fuel load
spare tire properly mounted in trunk
no other items in car (including people)
tires inflated to door label specs
And, of course, the measurements are based on using the OE tire sizes.
Navy Lifer
Anyone know where I can find the measurements for a stock ride height on a 9C1 and a SS? I'm considering new springs and don't want to be disappointed. I guess anyone with an SS can measure from the ground to the top of the wheel well and I can compare that with mine. (Depending on tire/wheel...
www.impalassforum.com
This is a case where words are better that a thousand pictures.