69 Road Runner, restored, new tank, oem thick retaining ring, vent lines are not reversed in the tank (scoped it to see), exterior vent lines are new and hooked up properly. When I drive in hot weather, engine hot, then stop and turn it off it sometimes burbles or bubbles (sounds like boiling fuel but s not hot enough to do that) it will barf out some fuel from the vent line sending unit area (not exactly sure where as I can't physically jack up the car and get underneath it fast enough to check). It will stop making bubbling noises when I open the cap. When I do open the cap,when all this is happening it blows out, pressure is definitely building in there some how.

Please help. Anyone else experience this?

Thanks in advance for your replies