I need to install sill plate on block begining this week and the mason has left me in a mess. The block is out at least 1 1/2" higher in one area the the rest of the block around the perimeter. Also there is a center support wall running through the basement which is 1" higher than perimeter and it is the center support for I-joist which will span from one side to other. How do you go back and compensate for this with sill plate? Can you go back and level the top of the block in anyway? I thought of pouring a 6" cap ontop of block to make it level all the way around perimeter what you guys think?