I am an amateur DIY'er and did an amateur screw up. Now I need to figure out my options to recover. Here is some backround: I'm plugging away at my crawlspace-to-basement project. My original post describing the project is HERE. I'll have a "L" shaped retaining wall that runs between 18" and 42" in height. The wall is non-structural (for lack of a better term) as it is positioned just outside the 45 degree slope from the foundation footing that my engineer told me to stay out of. This weekend I poured the footing for the wall. Instead of using my rotating laser to guide the height of the footing, I (like an idiot) used a length of PVC pipe that I could hold against the joists above to gauge the concrete level. That was not such a good plan because I got out my laser out today and realized that the height of the footing the surface varies about 7/8" between the highest and lowest points along its length. I suppose that I could gradually make adjustments in mortar joint thickness over each course so that the top course is level. However, I'd like to make as big an adjustment as I can at the bottom - the one joint that the floor slab will hide. So, how much can I fudge the thickness of a mortar joint either above or below the standard 3/8"? I am overbuilding the rebar (verticals are spaced 16"-24"). Does this extra strength allow me more wiggle room with the joint spacing? Or, are there other solutions I am not thinking of? Thanks a lot.