Need opinions and facts.

Had a Mechanic tell me his son insists on using 96 Octane Lead Replacement Fuel, which is available in Australia.

I know Unleaded Fuel has been available (only) for maybe 10 or 20 years in North America.

As you know, I drive a 1981 244DL with B21A, Zenith-Stromberg Carb, and BW55 Auto Trans. My Owner's Manual does not mention any requirement for "Leaded Petrol" (Gasoline). It only specifies minimum Octane.

We know Tetraethyl Lead was used to effectively increase Octane and provide Valve Seat Lubrication. We all know about the effects of ghetto children eating Lead Paint Chips and inhaling Leaded Petrol Fumes belched from Momma's Welfare provided Cadillac . . . when she was between US Postal Service and Government jobs.

But, let's keep this focussed on what, if any, effect the use of Unleaded Premium has on Volvo B21 Engine Valve Seat Recession.

Does anyone really know what time it is? Does anyone really care? Does anyone really know the truth, whether the 1977 to 1987 Volvo Valve Seats, Valves, Stems, and Guides, from the Factory are hardened, sufficiently to tolerate Unleaded Fuel, without additive Upper Cylinder Lubricant, and not suffer from abnormal Valve Seat Recession?

Seems there is no concen real agreement on the internet? I saw the B20 Engine, stuff, but he abused his engine (racing). I am talking a different engine and everyday family car, city driving, some highway, some up steep hills.

Thanks.