Your doing the pullovers advantagously. ive seen ppl lay on the bench as if doing a BP and hang off the end doing nose breakers /french curls. i think i read in enclyo of BB by Arnold that he used pullocers to expand his rib cage which added to that massive chest.
Peary Radar's 20 squat program had the pullovers and mentioned using a light weight. But my question is-when does the body not stretch anymore using the same old 25lbs where a 30 or 35 would keep that stretching. I definately wouldnt turn the pullover into a core lift and maxing out.
Also along with this 20 squat program he had DLx20 routine and a PCx20.