Lead additive needed?

[scottydl]

I've been watching an '88 Mallard Sprinter Class A at this eBay listing and noticed a comment from the seller about using a lead additive with the Chevy 454.  I asked them about that, and the seller told me "There is a decal by the gas tank that says LEADED GAS ONLY. So, I have always just put the additive in." 

Is this a common requirement?  In the 100+ 1980's motorhome ads I've looked at online, I've never seen this mentioned any other time.  I'm not real serious about this unit in particular (been sitting for 3 years, 9 year old tires, etc.) but just wondered about it needing leaded fuel.  ???

 

[King]

I am reasonably sure in a 1988 vehicle, the original decal said "unleaded gas only"  The GM 1971 Owner's Manuals state that all 1971 GM engines can safely use unleaded fuel. ...
Art