1 quant == 1 pixel at 16 bit texture image

so a texture that is 128x128 x16 ( such as the defualt texture) will take a block surface 128 quants wide/tall/deep , from starting at the origin, untill the texture 'tiles'(repeats) itself.

the origin point of the level is being where ALL texture tileing originates from, so being you want a texture to fit exacly on a surface. place the block at the origin, line up the texture.. then texture lock the block before moving it to its final possition in the level.