OK, so you got me out of my computer chair, out to the chilly garage...
As accurately as I can measure we'll call it slightly over 10" (still talking center stands here, guys!) between the pivot pin center and the bottom of the foot. The Indian made center stand on my Redditch frame project works much better than the cast original I had on a '58 Bullet, so it is worth doing, BUT it will only work if your twin has a Siamese exhaust pipe - see Hitchcock's part # 92837, which includes a new set of rear engine plates, pivot pin and springs, not a bad idea if the original pivot pin hole is badly worn. Bronze bushes and grease nipples were sadly missing from the design, something our Indian friends could have improved on, instead of perpetuating a Redditch weakness.
Hope this helps.
A