Mining system scaling issues

Any idea how I can get this to scale down in one direction, instead of both, as shown in the picture below?

Script:
Mined.Size = Vector3.new(Mined.Size.X, Mined.Size.Y / 1.2, Mined.Size.Z)

It scales from the center, so you need to move it down by half of the removed height.

local delta = Mined.Size.Y * -0.2
Mined.Size += Vector3.new(0, delta, 0)
Mined.CFrame *= CFrame.new(0, delta / 2, 0)

If this is within a model you can use Scale, that will affect the whole thing equally.
Like when you highlight an object and press Ctrl+G … puts it in a model. Makes sizing pretty easy.