Rons write,my opinion& exp. isgo with pressure treated Bottom plate[use cheap mat under plate so as no contact with concrete]plumb /level up,& nail to [sister to your ceiling joist& rock.OR you can use a top plate too,nailin to the joist,im sorry but you will bust ur arse doin it any other way,MY very stuborn father in law never agreed but did this MY method& others im sure oppose to screwin around with the blocks & screws&mason bits & such