Heidi, 1st please use two "A"s and no "E" in Camaro, thanks.
2nd, monos give a nice soft ride (if they are in good shape) paired with the proper shock. If the monos are tired and sagging, you can have them re-arched at a local truck spring repair shop (1.5 inches over stock height is good). Or replace them, new monos are available in most parts places, Eaton spring is a good place.
The multi-leaf spring is better for higher HP and cornering. If your rear end is a mono spring rear, then you need to swap rear ends, weld multi-leaf perches (which are deeper) or use extension blocks to properly mount the thicker springs.
So give us a bit more info on what your car is and what your goal is.
I have a mono leaf convertible. I had the springs re-arched 1.5 in over, put some good shocks and new poly bushing on and it rides just fine.