I replaced insert in roof of a 34 chevy sedan ,i used a chevy surburban roof panet cut to fit it has reinforcement ribs and cross ribs ,cut the side ribs long so they attach to side panel and roll down sides makes much stronger no flex , a freind replaced his with flat sheeetmetal ,did not work to well flexed made noises ,,oil cannin, not a good choice. hope this helps you.
