3.5 injectors, according to online resources I can find, are rated the same as 4.5 ones.

What you want is modern injectors (with a custom fabbed fuel rail presumably) that will have a lower rate of delivery but better fuel atomization to better combust and raise efficiency.

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

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1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k