moving a part inside the players head?

wait(0.5)
part = Instance.new("Part")
torso = script.Parent.Torso

part.Parent = script.Parent

part.Position = torso.Position
part.Size = Vector3.new(0.2, 0.054, 0.2)


weld = Instance.new("WeldConstraint")
weld.Parent = torso
weld.Part0 = torso
weld.Part1 = part
part.CFrame = part.CFrame - CFrame.new(0,0,0) -- trying part.Position = part.Position - vector3.new(x y z) did not throw an error but would refuse to move--
part.Transparency = 1

Im trying to move a small part at the center of the players head. when I used position instead of CFrame the part would not move at all when vector3 is set to (0,3,0) but If I set it to (0,5,0) it suddenly moves to the feet. changing it to something in between doesn't cause the part to move at all it stays were it is. I tried using CFrame instead but roblox throws an error. ( I used the torso as the parent for the part and it shouldnt make much of a difference if it was paired with the head)