Peterbilt 567/579 Fuel Tank Caps: Need a fuel cap for your Peterbilt 567 or 579? This lineup's got it all?vented, non-vented, locking caps, and even anti-siphon options. Perfect for fleet managers or owner-operators, these caps are tough, secure, and built to fit like a charm. Whether it?s a simple gasket or a full assembly, keep your refueling system running smooth and hassle-free!