I know that everyone wants to blame the rubber. But if you go back and look in any Ford service manual from 1965 up they all tell you on the first page to block the control arms or you damage the bushings. Not us making it up Ford put it in the service manual for a reason.
A coil springs has thousands of lbs. of stored energy the bushing on the shock is only resisting the charge in the shock and the valving.
As far as two post 4 post. If you lift on a 4 post you still have to jack the front so does the same thing.
I will scan the Ford manual today and send on this link. It is part of the normal service on a Mustang, Maverick, Granada and others that use similar front suspension.
I had just put brand new ones on and forgot to block and busted one the first time I lifted it and they were NOS originals not Chinese.
I saw someone also say they jacked under the front end. You should never jack a mustang up by the front cross member or under the engine. You can and will bend the chassis not designed to take the loads in that direction. You can jack under the lower control arm the little u brackets welded to the bottom are for jacking there. The torque box is other lift area and of course the front mount on the rear spring.
It is all physics equal and opposite reaction. When new people would sometimes crack windshields lifting incorrectly. These are very weak chassis and with rust even weaker.
