Quaternion.LookRotation with an offset.

Hi everyone, this is my script :

 function Update () {
 
 var hit : RaycastHit;
 var ray = Camera.main.ScreenPointToRay(Input.mousePosition);
             
     if (Physics.Raycast(ray, hit) && !Input.GetMouseButton(1) && !Input.GetMouseButton(2) && hit.rigidbody && PartPlacement.gui == false) {
                 
         transform.position = hit.point;
         transform.rotation = Quaternion.LookRotation(hit.normal);
                 
     }
     
     transform.eulerAngles.z = PartPlacement.rotation;
     
 }

I am trying to make a rotation offset for Quaternion.LookRotation using eulerAngles. The code that I have so far does its job perfectly until the transform is aligned with y axes. Then instead of being an offset static float "rotation" becomes a rotation speed value or in other words instead of degrees it becomes revolutions per second. I need Quaternion.LookRotation to stay in the script if possible.

It's fixed!

Full code:

 function Update () {
 
 var hit : RaycastHit;
 var ray = Camera.main.ScreenPointToRay(Input.mousePosition);
             
     if (Physics.Raycast(ray, hit)) {
                 
         transform.position = hit.point;
         transform.rotation = Quaternion.LookRotation(hit.normal) * Quaternion.Euler(0, 0, PartPlacement.rotation);
                 
     }
     
 }