Yes, the 2.3l Duratec has 4 valves and just one spark plug per cylinder
4 valves is a better use of head space, than dual spark plugs
You don't ever need to change the intake side spark plugs
You have a 2.5l SOHC Lima engine, a stroked 2.3l SOHC Lima engine
This engine ran fine from 1974 thru 1988 on just 4 spark plugs with a distributor
Dual spark plugs were added in 1989 when Ford switch to distributorless spark system, which makes dual spark plugs easier to add
All engine makers knew/know that dual spark plugs added more power, pretty much since gasoline engine were invented
But if you have a distributor you end up needing this:
https://i.ebayimg.com/images/g/CLUAAOSw0eBjF4za/s-l1200.webp
Need 2 coils and 8 wires
6cyl dual spark distributor cap:
https://forums.pelicanparts.com/uploads20/nummers+rechts+dr1333595112.jpg
Without the distributor it is a lot easier, and you get more power, so why not
Dodge Hemi ran dual spark plugs for awhile
So why don't they make all engines dual spark plugs now?
Because 4 valves instead of 2 valves in a cylinder adds even MORE power, so a better use of head space
The 2.3l/2.5l Lima was replaced with 4 valve 4cyl 2.3l DOHC engine with single spark plugs
So you can just change the exhaust side plugs as needed and your engine will run just fine, slightly less ADDED power but will run just fine, as it did 1974 thru 1988
The only time you would have a spark misfire is when BOTH spark plugs in a cylinder failed to fire