My 65 tall....

With a tank Of that height (I own one as well) I wouldn't do it without repair. The glass will need the brace. these tanks bow considerably when filled. Since the tabk is empty, you could easily silicone a sheet of glass on each side of the existing brace making it 3 times as thick but with contiuous glass on each side of the crack it should suport the tank. That much surface area of silicone will have phenomenal strength. The other option would be to get a new tank rim that has a plastic cross brace. they can be hard to find but are available. The trick is finding one that exactly fits your tank demensions. Glass cages.com may be able to help, as well as other manufacturers.