Pinning gears on IMS?

[Homeoboxter]

Hi All,

I will soon get to start reassembling the engine and it is still a bit unclear for me why the valves were touching the pistons. This makes me wonder if my IMS gears are still aligned and not rotated with respect to the shaft. How can I test this? Also, since the IMS is out now, would it make sense to pin the gears?

Thanks for any input.