Manual talks about 6 G´s on recovery of Ju 87 B-2 version, on radius of 450 meters... Page.29 ( I do not think Ju 87 Ds were different in structure, but engine etc.!)
https://ww2aircraft.net/forum/thread...-manuals.5504/
But it so happens this is target G. For enduring 6 G safely (I have done this often!) you need have 50% safety factor built-in and material safety factor (10% to 25% depending on material, so 11,25 Gs is very good, but not good enough for modern fighters!). But just slightly damaged structure reduces this. Saying 9 Gs is just a figure, one can also say wings could be long gone by then, if encountering strong gust, say -/+10 m/s gust as Modern Gliders must endure. Here fatigue cut in (and is the reason for 25% material over design, usually ...)