Engine should run well for it's age and miles but the only thing listed that will change the power doesn't add any power just lowers where the power is in the RPM band.
The headers move the power band lower in the RPM range.
Stock ranger has cold air intake and over 150% flow, so engine already has access to more air than it can use.
And it has a tuned exhaust, but tuned for mid-range power.
Tuned exhaust means the pressure at the exhaust valves/ports actually goes into negative pressure at a specific RPM, so in that range in the RPM band the engine doesn't have to push out the exhaust, it is sucked out so crank doesn't have to use any power and that means extra power for the rear wheels.
Tuned exhaust has to do with pipe size and length, you want exhaust to get a good velocity going so don't want pipe to be too big at the head, this velocity creates a low pressure when it gets to the collector(larger pipe), so each exhaust valve opening increase velocity and lowers pressure at the other exhaust valve on that bank as RPMs increase.
Size and length of the pipes creates the lowest pressure, so more engine power for rear wheels at specific RPM.
The exact Science is beyond my pay grade, lol, but have read some racing headers could create -7" pressure at peak.
But most want lower range power not high RPM power so that is what most headers are designed for.
And it is just moving the power band lower, no increase in overall power.
And outside of being plugged up, Cats and mufflers can't effect power at all, but they can create a good sound.
No manufacturer "de-tunes" an engine, so tuning a stock engine really isn't needed.
If you can't increase the compression ratio or the displacement then all you are doing is making a good running stock engine.
It will get peak MPG and peak power but just what it was made to do when new, nothing extra.
Yes, it will be a nice looking good running Ranger
Last edited by RonD; 08-01-2015 at 11:18 PM.