Tedious Packing and Brilliant Underhanded Ideas

So our group is heading out of NYC through American Airlines and transferring to China Eastern Airlines in LA. Now the problem is that AA only allows checked luggage to weigh 50 lbs where as CEA allows 70 and I just can't seem to get my suitcase any lower that 58 lbs. So I got to thinking, AA allows one carry on and one personal Item (PI being a back pack purse or briefcase etc). Where as CEA does not, they only allow one carry on. So I was thinking what if I put extra stuff in a back pack and then transfer it to my suitcase when we switch to CEA. Hmmmmmm, just might work.