Well, having had a 91 Ranger 4.0, and now in a 01 Ranger 4.0 SOHC, Basically I am not sure you would want to do much to the engine.

Aside from having great torque OEM, there isnt a whole lot of aftermarket support for these engines.

Air, exaust, and some other minor area's are all I have considered in my short bed regular cab 5-speed manual 2x4 Edge, and quite honestly, I can bust-em loose anytime I want even in 3rd.

As far as premium fuel goes, I know for a fact that there is significant improvement in accelloration and top end power in my motor using the good stuff.

I have noticed though that on regular gas, my motor almost seems more responsive with a minimal to average load in the trunk.

Regardless, 4.0 is the way to go if you drive a Ranger imo.

so i went with the dynomax exhaust. the roush was 2 much. sounds good tho

__________________
haul ass and suckin gas