how for should wheels drop the on stands

I came across a picture of a vette (C4) on jack stands and someone had commented that their wheels were hanging too far down - but they never commented on what that meant - I was curious if someone here could help - I have not had mine up on stands yet this year but I remember thinking in the fall when I had it up that they seemed to hang down quite a bit.  I did not think much of it at the time because there did not seem to be any issues - but that image and comment made me think a little.  I wish I could remember where I found that at - but at the moment I cannot 

any help/thoughts or opinions would be great 

thanks

Sean

They drop as far as the suspension allows them; then they'll usually hit the snubbers, or are limited by shock travel.

thanks - after looking at other pics it just seemed like some hardly drop at all while others travelled a little more