Hey, I have a 91 7.3 idi NA and was wondering if you guys had any recommendations for tuning it up. it runs really well at highway speeds so I'm not really looking for more power (but I'm never opposed to that) instead just looking to get the best mileage out of her as i can. Thanks!!

 

Good synthetic oil, big air cleaner ... Ditch stock , and open up exhaust to allow for better flow ... 4" is what most run ... Off the Y then to 4" ... I get 18-20freeway .... With 35's