What surface does your storage area have? If it's dirt or gravel, fabricate some square pads from pressure treated lumber for the jack stands to sit on. I use 2 X 6's with a couple of cross braces made of 2 X 4's. Stand bases can penetrate into a soft surface and allow the vehicle to become unstable. Ditto on supporting the frame. Don't forget to seal off the intake and exhaust to keep humidity from getting to the cylinders through open valves and rusting the cylinder walls. Use fogging oil in the cylinders first.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!