Well I don't know about damage but the shock is sprung weight and even more so when the can is up.

Well I think it is less "sprung weight" with the body up as it will then be mounted on the body and not the axle, butt being as noone here is running a fomual 1 car it would not matter eather way .

butt I do thijnk that if I were going to run some shocks "up-side down" I cut the dust cover off so it would trap drit.