How Can I Show Cloned Block Position?

I want to show a cloned block before placed. How can I fix this script?

  --Intilaze Player's Mouse
  local playerMouse = game.Players.LocalPlayer:GetMouse()

  local Gridsize = 4


  --Tool Equipped
script.Parent.Equipped:Connect(function(build)


    if game.Workspace.GameRunning.Value == true then
        while script.Parent.Unequipped do

        local CBlock = game.Workspace.Block:Clone()


        CBlock.Parent = game.Workspace
        busy = true
    repeat
        wait()
    CBlock.Position = Vector3.new((math.floor(playerMouse.Hit.X / Gridsize  ) * Gridsize),(math.floor(playerMouse.Hit.Y / Gridsize + 0.5) * Gridsize) , (math.floor(playerMouse.Hit.Z / Gridsize ) * Gridsize))
        --Mouse Down Event
        build.Button1Down:Connect(function()

        CBlock.CFrame = CFrame.new((math.floor(playerMouse.Hit.X / Gridsize  ) * Gridsize) , (math.floor(playerMouse.Hit.Y / Gridsize + 0.5) * Gridsize) , (math.floor(playerMouse.Hit.Z / Gridsize ) * Gridsize))
       busy = false

         end)

    until busy == false

        end



    end



end)