Older Cars From 1940 Or So Will They Use Today's Gas?

This is a Ford Eifel from around 1938 or so and I wondered if today's gas will work or does it have to be doctored in some way like some older cars need higher octane or is that even true?
I'm just curious so don't waste time bustin' my chops over it.
Thanks and thumbs up to all who answer… Just give me time to get back and read the answers.

Usually the car engine will have been modified, or need to be modified, to run without the added lubrication of lead to the valve seats

TIMBO is right and there's ANOTHER complication now that our unleaded fuel is also LOW SULFUR fuel! The VALVE seats on older cars before the 80's made in THIS country all needed mods to the HEADS to burn unleaded fuels! Then they used SULFUR as a lubricant, and NOW there are MORE fuel changes done! I never heard of putting BALLS in the tank but it sounds like it would work! It is NOT about octane at all but about how the fuel ils burned and how the VALVE SEATS can take it! Many EUROEPAN cars needed no mods a\to adjust to the UNLEADED fuels used now. ASK owner if they know about anythign donem to VALVES and VALVE SEATS on this car!

Not entirely, as today's gas is unleaded it has not lead in, the older engines and carbs were tuned in a way to have leaded gas. People usually put lead balls in a cage in there petrol tank and this works fairly well. Some engines can run normal gas fine, We Had a Fiat Twin cam and that ran just as good on normal fuel. But some lack power

Either stelite or ductile iron valve seats are needed so that unleaded fuel won't burn them. The only other issue is something called RVP or reed vapor pressure. In the old carburetor days RVP of fuel was a high number. How quickly fuel vaporized. At low carb. Fuel pressures this is necessary. A carb usually needs about 4PSI fuel pressure unless you are racing. Older cars it's even less than 4PSI. Todays fuel injected cars have anywehere from 35PSi on up to 70PSI some have more than that.
because of a low RVP today vapor lock is prominent than it used to be. I have a 1965 mustang. It isn't stock. 425 HP 302 V8
my fuel line is insulated and I run 7PSI fuel pressure to prevent vapor lock. IT still happens. I need to modify my fuel system and add a fuel line returning unused fuel to the tank. With a higher volume fuel pump than what it has now I'm hoping to solve this issue. I live in Idaho, today is only 95 so I'm ok. When it gets over 100 gegrees I have an occasional vapor lock issue.
essentially the fuel vaporizes in the fuel line and the fuel pump can't push fuel past the bubble so the engine stalls.
so a quality machine shop can install ductile iron valve seats and do a valve job for reasonable prices.
hope this helps
RETIRED SENIOR MASTER TECH