Dang it my mistake. I thought he was talking about the distance of the perches, his word, rather than the hangers...
EDIT: Ok, I realize he's talking about the perches, in relation to the springs after a relocation. The rest still applies. Measure 14 times, cut and weld once.
To make an 8.8 fit into the stock location, 2-7/8 is removed from the long side.
To adjust for the relocation, he needs to just go with ground truth with the car assuming everything is "correct" and the leaf springs are vertical and not canted slightly one way or the other. If not, that could easily account for 1/2" on each side. With a relocation kit are the springs now parallel as measured between front and rear? If so, it will be a lot easier to get the right distance. Geometry doesn't lie.
Whatever the case may be, the second video goes into making the correct, if tedious, measurements to ensure everything is aligned and centered properly.,
