Any harm to vintage engines running unleaded fuels. Options

[914043]

Back in the day when they took lead out of gas there was a lot of concern that without the cushioning effect the lead had on the valve face there would be bent and broken valves. Since my car fits those criteria and will be driving soon what if any concerns should I be aware of?? Fairly technical but Thanks for any help that might save me a damaged engine. Best to Ya

[Van B]

As @Superhawk996 described, you can rest assured that if you have aluminum heads, you’ll be fine with unleaded. But, until anti-knock sensors came around you did have to pay attention to the minimum octane rating. In the US we use the (RON+MON)/2 with motor octane being a lower number than research octane, you won’t see our fuel numbers matching the RON only number, but the measure I’ve always used is to add 5 to the number at the pump to know if it’s high enough octane for you engine’s listing in RON. For example, 91 RON means you can run 87 octane from a US pump.

@wonkipop I think the heads may have been different due to runner configuration for the carbs.