driveshaft length rear diff swap

I've got a drawing here somewhere that shows 3 differentials and their dimensions.
I would need to hunt it down to be certain that it showed 171/4 difference between 7.25 and 8.25 . Since it came from the interweb too, I don't know its accurate.
Having said all that.. 3/8 inch either way will get the end seal to a new center of travel on the front yoke. I would rather go to the short side. I sure wouldn't want to bottom the slip yoke and damage something.
I suppose measure twice and cut it once applies.
3/8 one way or the other doesn't matter ? ( that's what she said ). :)