godot3 how to rotate x or pitch correct to target align?

Question

Tired to get part of pitch to work but the rotate is not working correct as I know little about how it work. Just trying out it but not sure how to get the math stuff work out.

Here the sample build. https://github.com/Lightnet/gd3mechs/tree/be95c65eacdcfa21daa84ab7e3f39530655f6194

TurretTarget.tscn < Scene test.

extends Spatial

var camera
var mouse_pos = Vector2()
var point
#var dir = Vector3()
var skeleton
var bonename
var boneid
#var base = Vector3()
var basepos = Vector3()
var pitchpos = Vector3()

var angle = 0

func _ready():
    camera = get_node("/root/Node/Spatial/Camera")
    skeleton = get_node("Armature/Skeleton")
    set_process(true)

func _input(event):
    if event is InputEventMouseMotion:
        mouse_pos = event.position

func _process(delta):
    # Called every frame. Delta is time since last frame.
    # Update game logic here.

    # Project mouse into a 3D ray
    var ray_origin = camera.project_ray_origin(mouse_pos)
    var ray_direction = camera.project_ray_normal(mouse_pos)

    # Cast a ray
    var from = ray_origin
    var to = ray_origin + ray_direction * 1000.0
    var space_state = get_world().get_direct_space_state()
    var hit = space_state.intersect_ray(from, to)
    if hit.size() != 0:
        #point.transform.origin = hit.position
        #dir = (hit.position - get_global_transform().origin).normalized()
        #basepos = hit.position * -1 #default?
        basepos = hit.position
        #basepos.y = 0
        #pitchpos = hit.position * -1
        pitchpos = hit.position
        #pitchpos.x = 0
    setbaserotation(delta)
    setpitchrotation(delta)

func setbaserotation(delta):
    bonename = "Base"
    boneid = skeleton.find_bone(bonename)
    var chassis_transform = get_parent().get_global_transform()
    var turret_transform = skeleton.get_bone_pose(boneid)

    # vector for rotation axis of turret
    var turret_up = chassis_transform.basis.y.normalized()

    # plane trough turret
    var p1 = turret_transform.origin
    var p2 = p1 + turret_transform.basis.x
    var p3 = p1 + turret_transform.basis.z

    var plane = Plane(p1, p2, p3)
    var look_at = plane.project(basepos)
    if typeof(look_at) == TYPE_VECTOR3:
        var x = (look_at - turret_transform.origin).normalized()
        var y = turret_up.normalized()
        var z = x.cross(y).normalized()
        var quaternion_current = Quat(turret_transform.basis)
        var dir = Basis(x, y, z)
        dir = dir.rotated( Vector3(0,1,0), deg2rad(90))
        var quaternion_new = quaternion_current.slerp(dir, delta*3.0)
        var transb = Transform(quaternion_new, turret_transform.origin)

        skeleton.set_bone_pose( boneid, transb )

func setpitchrotation(delta):
    bonename = "turret"
    boneid = skeleton.find_bone(bonename)
    var chassis_transform = get_parent().get_global_transform()
    var turret_transform = skeleton.get_bone_pose(boneid)

    # vector for rotation axis of turret
    var turret_up = chassis_transform.basis.x.normalized()

    # plane trough turret
    #var p1 = turret_transform.origin
    #var p2 = p1 + turret_transform.basis.x
    #var p3 = p1 + turret_transform.basis.z

    var p1 = turret_transform.origin + turret_transform.basis.y
    var p2 = turret_transform.origin
    var p3 = turret_transform.origin + turret_transform.basis.z

    var plane = Plane(p1, p2, p3)
    var look_at = plane.project(pitchpos * -1)
    if typeof(look_at) == TYPE_VECTOR3:
        #var x = (look_at - turret_transform.origin).normalized()
        #var y = turret_up.normalized()
        #var z = x.cross(y).normalized()

        var x = turret_up.normalized()
        var y = (look_at - turret_transform.origin).normalized()
        var z = x.cross(y).normalized()

        var quaternion_current = Quat(turret_transform.basis)

        var dir = Basis(x, y, z)
        dir = dir.rotated( Vector3(1,0,0), deg2rad(90)) #rotate x
        dir = dir.rotated( Vector3(0,1,0), deg2rad(180)) #rotate inverse
        var quaternion_new = quaternion_current.slerp( dir , delta*3.0)
        var transb = Transform(quaternion_new, turret_transform.origin)
        skeleton.set_bone_pose( boneid, transb )
    pass