[William]

I've heard that also, primarily concerning LA built cars.

One of the Camaro club magazines had a factory photo of a worker in a pit under the line with a paint wand, possibly applying sound deadener in the wheel wells and driveshaft tunnel. Having spent more time under Camaros than in them I know they weren't very neat about it. I've seen the stuff on driveshafts, axles, exhaust hangers and the fuel tank. But it was overspray, not a deliberate coating.

No one has seen all 700,000 or 1st gens and it is possible some tanks were undercoated. But it was not as we say, a normative practice. All of the original magazine road tests I have with chassis photos show an uncoated fuel tank; same as the many Camaros I have had personal experience with. Our '67 Z/28 was dealer undercoated (ugh) and they didn't do the tank. Wouldn't make much sense as any black surface will absorb heat.