Replacing a load bearing wall between kitchen and dining room. Looking to have the space appear as one large room. Removing the interior wall which supports 1/2 the 2nd floor (2nd floor floor joist change direction in center house. Front to back for left side to center of house. Left to Right joist from center to right of house. Old house. Basement has a 8"w x 10" beam under wall to be removed. Looking to place header under the 2nd floor joist that need support (8 Joist over a span of 9' - using two 2x8 LVL as header).

Was hoping to bury the Jack Studs on one end into the exterior wall, so wall would be smooth between dining and kitchen. When removed lathe and plaster, there is a 4" x 6" (actual dimension) post in the wall that runs from sill to roof (balloon framing). I'm not going to cut into this post, but would like to attach the header with steel bracket or something to eliminate the Jack stud. Since I have this 4x6 post, can I use this for support and how to achieve my smooth wall between dining room and kitchen. Other end of header is not a problem with structure as nothing is in the way and I have structure all the way down to the foundation.

From what you have given us, the age of the home and the joist changing, I think you need to have a structural engineer give you an evaluation. This is a very old structure if it has a true 4x6 post and a 8x10 beam. A previous owner may have already made some changes that were not part of the original house.