Earlier on he has a video on a cheap way to show and balance rods.
The grinding on the rods is nothing new. I have a 360 that the rods were smoothed down and shoot peened. It was expensive to do but it’s worth the cost if you’re going forth with all of these little tricks. Once you know how to do the work and do the work yourself, you’ll probably appreciate the cost of the machinist to do the work. It’s very time consuming to do.
When you do all the little tricks all over the engine, for what it is, the combination of parts all together, it’ll out run an equally built engine and others will be saying, it runs really well for what it is. They will know somebody spent some extra time on the engine.