I have a home built in 1956 that has a load-bearing wall that is about 2ft off the main support beam in the basement. There is currently a 30" opening in wall with 2x4 header. I would like to extend the opening to 72" and support with an appropriate size lvl beam. The width of the load is 24ft wide but supports a second story and rafter roof. There has been no evidence of cracking with the current wall. Are posts in the basement required?