Street Tracker Tank Alternatives?

[Quinn]

I'm building my first street tracker and am having second thoughts about going with a fiberglass tank. It seems that there is concern about gas eating through the tanks and causing problems with the carburetors and so on. I've been looking on eBay and there are quite a few vintage metal tanks from other 70's Yamahas (mx250a, mx360, R5 350). Has anyone ever used one of these? Thoughts? Pics?

Thanks,