[97chevyman]

I would not use a K and N filter, there are better setups out there. On another forum which i post on, a person had a construction company, and would spend approx 1000 dollars in air filters a month for his fleet. He tried K and N and sent in an oil analysis before and after the change. Silicon levels ( dirt ) in the oil almost thripled. Tymar makes a nice intake. Is your truck carbed or injected? My memory is a little fuzzy on when ford switch, i have heard 86 and 87 both. If it is carbed, maybe get a better carb, such as a edelbrock 750. I know this sounds strange to put a larger carb on your engine, but with the use of a larger carb, you are not opening your secondaries, only primaries, thus saving gas. Plus if you get a cold air intake, and throw on dual exhaust with headers, you should expect better MPG. Also a good truck cam would not hurt. The easier the motor can breath, the better fuel milage you will get. As for the exhaust, if you decide to put on duals, have the installer install x-pipes. For then you can run dual 2.5 inch pipes and still have tons of low end torque. The reason for this is exhaust scavenging. Here is the easiest way i know on how to explain this. When a semi is going down the road, there is higher pressure in front of him and lower in the back. When your exhaust valve opens shouves air out, it goes down the pipe, then by the time the next cylender blows out the exhaust, there is a low pressure area right where the exhaust valve is making air come out easier, more torque and engine power on low end. Well with larger pipes, more volume, so less pressure, making better top end power and better MPG, no low end torque. With the x pipe, it makes 2.5 inch pipes scavenge like they are 1 7/8 pipe, best of both worlds. Good low end torque, good gas milage, good high end for passing power. The RV cam will be open longer than the stock cam, making the cylenders breath better, making more power, and with more power for the same fuel, equals better MPG. Hope this helps.