I am taking out a supporting wall between two bedrooms in a basement rancher with a garage underneath. I have put in a beam in the attic above. One end bears on the outside wall. The other halfway between two steel posts set into the garage floor. The floor beam is marginal for the added weight of the drywall ceiling to be added to it so I am considering bolstering the beam with an added 2x flange underneath or adding a post. The flange will be difficult because of HVAC ducting thats in the way. Adding a post would be easier.  My question is whether I need to cut the floor and add a footing under the post or just put the post on top of the concrete floor?  The floor is 50 years old and has no cracks in it (it’s unpainted so I can see it clearly. I assume its 4″ thick, but don’t have a way to tell. About 150 sf of new ceiling will bear on the attic beam, with half to be on the post–about 1000lb @ 15 psf for the ceiling load.

thanks