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)