Exhaust headers, other engine upgrades on '02 4.0L V6

[triggerz]

I only get about 15 mpg hi-way on my '02 4.0L V6 with manual trans. Has anyone tried boosting performance by installing exhaust headers, twin exhaust lines, or individual ignition coils per spark plug? If anyone has, particularly headers, what kind did you use? Results?

Thanks guys.

 

[TracerBullett]

'02 with the SOHC the only headers available are made by jba. Don't know anyone with them but the stock headers perform very well and unless you tow alot or run at high rpms constantly the headers won't help much. I've used headers in the past and I can tell you gas mileage will probably go down.