Rear end sag

the drivers side rear on my 74 pontiac catalina seems to be sitting lower than the passenger side. it was't like that the last time i took it out but i did notice it when backing in the driveway after a nice drive on NYC streets and potholes. i want to get it out the driveway so i can have it on level ground and even check the tire pressure. from what i measured, the passenger side bumper corner is sitting approx 1 1/2" higher than the driver side from the ground. i'm guessing that the springs may be in need of changing but i can't get my hands on some for 2-3 days. that presents a problem because i had plans to go to a swap meet this weekend in the car.

would it be very bad to drive it like this? i don't speed in the car and don't take corners hard. I figure the passengers/kids will sit on the passenger side because it has 6 doors and 3 benches. will it just look silly from the rear or would i be etting myself up for some type of catastrophic event?

thank you

Worn-out springs tend to sag relatively slowly and gradually. Such worn springs are still drivable, but not ideal, due to the negative effect on handling.

A sudden drop in car height is more likely caused by a broken coil. This may be a problem depending on where the break is. A break at the top or bottom is not so bad. But, while the car is still driveable it is not safe. It is effectively 'shorter', so if the rear axle attains near-full extension (caused by crossing speed bumps, railway crossings, etc) the spring can fall out, allowing the rear end to fall to the bump stops. This would drastically affect handling of the car. The spring may damage the car or other traffic as it falls out.

A break in the spring anywhere else is very unsafe and the car should not be driven.

i looked underneath and did not notice anything broken. it just looks like the driver side is more compressed than the passenger side. is there a specific way to check for a broken spring?
Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 8.12; MSIEMobile 6.0) VZW:SCH-i910 PPC 240x400

Get a new set, the things are 36 years old.

they're not that old. they could use replacing though. a lot of stuff could. fortuntely after getting it out on the street it seems to be level. i guess i just never noticed it uneven in the driveway before.
Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 8.12; MSIEMobile 6.0) VZW:SCH-i910 PPC 240x400

Have you looked at the contents of the car , particularly the trunk ? People often carry unneeded materials in the trunk . If the trunk has lots of " stuff " in it , the weight could be causing the car to sag or lean to one side . This is particularly true if the contents are heavy . This extra weight also lowers your MPG .

there's nothing in the trunk other than a spare and crate with fluids. it seems the back of the driveway isn't level and i just never noticed it before.
Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 8.12; MSIEMobile 6.0) VZW:SCH-i910 PPC 240x400