FWIW I know of two E bodies done in the 90's that had quarters hung with the weight on the suspension... Both had serious issues because things moved... My preferred method is a process using eight jack stands & shims... I also use a 6' level & a frame chart...I position a jack stand at each end of each frame rail, I shim those locations from side to side to get them truly level.... Then i use the frame chart the level & a couple 9" drop rods to set elevation of the rails front to rear... Done it this way for many years & I've never had an issue...
Kind of a poor mans frame jig...