Interesting decision by BackBlaze to stuff an extra row of drives in, lengthening the chassis to 33" instead of just under 29". It is their design, so they're free to do what they need for their own racks, but this does mean anyone trying to install a pod based on the 6.0 design couldn't use many closed-back racks or other kinds of racks.
But that was back in the late 90's/early 2000's, so things might have changed.
Another guideline in there that applies here is the one about not repeating the name of the company when it's already mentioned in the domain to the right of the title. That's a minor point, of course, but one that has had surprisingly good effects.
Also, the 6.0 housing will fit in most racks. If somebody can either measure their racks or include a link where the 33" chassis will no longer fit, we really want to hear about it!
Later in the bullet list of changes:
"Added 3 more backplanes and 1 more SATA card."