Headers will gain more better airflow on any engine.
Most people get headers for their Ranger off Mustangs that came with 2.3Ls who had headers on them. Best to look in a Mustang forum or make your own...keep searching the net.
1979 Ford F150 4X4, 7.5L, C6, 38s Super Swampers TSL
1978 Ford Courier 4x4, 2.3L carbed, 5 spd manual, dry-rotted tires
1985 Ford Ranger 4x4, 2.3L FI, 5 spd manual, 29s Power Kings
1990 Ford Bronco 4x4, 4.9L, 5 spd manual, 31s Maxxis Bighorns