I'm not sure exactly what resin is affected by modern fuels but fiberglass tanks are time bombs. I noticed mine seperating and mixing with my fuel, now I'm swapping tanks and I'm finding all that resin was depositing in my intake and cylinder heads when I was running. If you find an aluminum tank similar to your's you will probably save some weight as well, I noticed when I cut out my tanks that they were heavy on the glass layers. I think you should just keep an eye on them and look out for a set to replace them with.