Billy,
When I used to take my 81 to the local Vette Shop they would always unlatch the t-tops when lifting the car. The reasoning is that the car will have a certain amount of flex to it and if the tops are latched tight they could crack or shatter if the car flexes too much. How true is that? Not sure really but it makes sense so I always do it when jacking the car up. Better safe than sorry.
To relate something similar, my old neighbor used to work for GM Design Staff and when the IROC convertible came out he got one as a company car, he said that the amount of material they remove from the car allows it to flex so bad they were having the body crack right in half (not the frame, just the body). Not sure if they fixed that or not. So to me, removing the roof of the Corvette...or not having the extra strength in the first place may lead to flexing.
