This may help you and may not, but I can remember changing rear shocks on vehicles back in the 60's and having to support the rear axle with a jack to let the shocks loose.
The extended reach of the shocks was not long enough to bolt the new ones up, meaning the rear axle would hang lower, so once again to install the new shocks the rear axle had to be jacked up.
It's hard to imagine a rebound of that distance unless you take it off road and drive over rough terrain at some crazy speed.
Dan
