I am about to replace the rear shocks on my friend'* 1973 el camino. I was wondering if i should jack it up from the axle or the frame. The shocks go through the springs so im assuming that if i jack the axle up and remove the shocks and springs the back end would drop and possibly injuring me. If i jacked it up by the frame would the axle just me able to drop and hang there,oh by the way i am replacing the original air shocks with monroe air max shocks. Any advice is appreciated.

Jack it up by the frame leaving the tires just off the ground. Put jackstands under both is the safest way. The shock bolts can be a chore to bust loose. I have bent a Craftsmen ratchet handle with a cheater getting one of the lower bolts loose on an older vehicle.