Movin Block Like In A Grid Can Someone Help me?

I made a build tool for my game, But I tried to moving stud to stud. (When I click some here,I want to part move like to colliding to 4 stud grid.)

Here's Code:

  --Intilaze Player's Mouse
  local playerMouse = game.Players.LocalPlayer:GetMouse()
  local pos = 0


  --Tool Equipped
script.Parent.Equipped:Connect(function(build)
    --Mouse Down Event
    build.Button1Down:Connect(function()

        print(playerMouse.hit.p)


        local cwb = game.Workspace.WoodBlock:Clone()

        cwb.Parent = game.Workspace




         cwb.Position = playerMouse.hit.p
         cwb.CFrame = cwb.CFrame + Vector3.new(0,4,0)





    end)




end)