Belted tires / flat spots

[ohhawk]

This will be the first season that I won't have radial tires on our car before I store it for the winter. Since I sold them I now only have some new F70x14 Goodyear Polyglas ones to leave on. I'm concerned about developing flat spots on these tires if I park the car and leave it in our unheated garage for the Midwest winter. I've read pros and cons about putting your car on jack stands. Anyone here that can speak directy to these original fiberglass belted tires and whether they can develop flat spots? I know the bias ply nylon tires would and the radials would not but don't know about these which have 2 ply polyester and 2 ply fiberglass. Don't want to damage some not so cheap tires. Thanks.