Wow, I had never read about the 4.0V6 technical specs.
Looks like a “hot mess” engine.

They are gouging on the last remaining new valves in inventory.

I wonder about new rubber 4.0 timing belts price & availability too.

Alpar says the 4.0 intake manifold is a “new low rumble” design change compared to the 3.5
so odds are against the valve for the 3.5 being identical.

https://www.allpar.com/threads/chrysler-4-0-liter-v6-engines-minivans-pacifica-nitro.229977/

Looks like you need to visit the salvage yards to look at 2.7/3.5 valves to see for yourself.

I cannot help but remember that Ford had a valve to switch intake runner length,
and then were surprised to find the valve could be left off,
and the airflow “could choose for itself”
the lower resistance path to flow through,
and the Torque curve of the engine improved without the valve.

Personally I wonder about the
4.0V6 “tuned equal length dual exhaust”
and what engineering principles it might reveal?

Is there something special about exactly 3.58 inch stroke, science wise ?
Harmonics, perhaps?