i replaced my rear shocks on my 71 cuda and when i put the car back on the ground the rear is lower than it was before, tire will rub the quarter panel. i don't know what brand the other shocks were, and the new shocks are oem. What would have caused this problem?

Unless the other shocks were air shocks or spring booster shocks, the height should not be affected. Oil filled shocks (stock) will settle to the normal sprung height. They don't hold-up the suspension.

Hi Sunroofcuda,
the others were not air shocks, the car was lowered 2", 10 years ago when i put on new springs on the car. at this point the car is undriveable due to rear tire rub.

I don't have an answer but I would put the old shocks back on for a quick test just to see if they raise it back up. & maybe compress both shocks to the height you have between shock studs with no shocks on there & see if they are smooth or tight/binding at that dimention.

Take a look at the rear spring shackles, which way are the spring ends of the shackles angled/pointed, towards the front or rear of the car?

Oem as in 40 year old shocks?..

they are new shocks purchased from summit racing.

I suspect the old shocks were stuck in a position, or the rear spring shackles were originally flipped the wrong direction therefore holding the back end up and are now correct position and are allowing the rear to settle down where is should have been.

The only other thing that comes to mind is that the rear springs are broken, and the old shocks were stiff enough to hide the problem. Gene