I have just had a quick measure up, quite difficult to get an accurate measurement now its fitted.
I would say that the 25mm distance is the one at the top.
Going to urge caution though............ I cut theese parts to the book length but because I had used thicker plate, I had to fettle a fair bit off to get them to fit in. !!??
I have test fitted the diff & am pleased with the fitment.
This was done whilst still on the build table.
Used an engineers square. The diff flange was absolutely plumb both up/down & side to side.
May be worthwhile having a re-read of the book though
