Slab and stand dimensions

[ihughes]

This is my first post so please have patience with my ignorance. Janet and I decided to build the 36'' oven and I'm trying to get my head around the slab and stand dimensions on in the materials and tools list.
The 2 foundation sizes (80x94 and 71x80) have the same materials and measurements for the rebar and framing studs, among other things. I've calculated what I think they should be and done a plan and it seems to fit. Are the similarities on the materials list correct?
And with the 63x70 block stand what are the 8x8x12s for? In my paper plan I can't find a use for them. My dimensions for a 63x70 block stand require 53 8x8x16 blocks and 2 8x8x8.

cheers
Ian