I need to close up a 24" width by 50 3/8 tall opening in a basement block wall. This opening leads to a old well pit under the outside steps. Old well is sealed. What do contractors do when the wall is the old size blocks ( 17.5 x 12 x 8) and new standard block are only 7 5/8 tall. 6 courses of 7 5/8 tall with 3/8" joints leaves a gap of 2 inches. How would they fill that gap? Slice a block down? Also, when adding vertical rebar and core filling, how do you do that on the top block? Because this opening in the wall is 4 sided, it is not open on the top. Once the block is in place, you can't get to the rebar to position it.