I'll give it a stab. I'd estimate just from observing, not with any measurements taht the rear will rise 1 to 2" on a tight car and up to 3" on a well loved car. I wouldn't worry about it until it starts clunking or othewise causing performance problems.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.