I don't know the 4r336, maybe it's the same as the new NH36 movement. I used that movement.
The movements are the same size so the spacer is the same. The stem and crown are different. the stem for my case had to be cut to 14.4mm IIRC. Also the crown at 4 requires a different date wheel. I sourced my parts here:
http://seikoparts.com/
I watched several youtube videos for mechanical hints.
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