Hey guys,

I have an 82 f100 with a 300 that i am soon to overhaul. right now im still in the planning phase of the rebuild and have some questions. I found this nifty intake kit at jegs and wanted to know what the MPG diff between stock setup and this one after the rebuild:

Offenhauser 6019-DPK Offenhauser Dual Port 6-Cylinder Manifold

While this truck wont be a true DD, it will get driven quite often. MPG and reliability are my two main concerns right now.

Thanks in advance!

Kyle

 

You don't want that if your main concern is fuel mileage. All that stuff is for air flow at higher rpms, to make more power at higher rpms.

For fuel mileage you want your engine barely turning any rpms while going down the road in high gear. That means you want the very small stock carb and the very small ported stock intake manifold. With a very low numbered gear in the rearend so the engine is barely turning over, that gives you the best fuel mileage.

 

Hey predator0121, welcome to FTE and the 80-86 forum.

Regarding the kit you have in mind, that will wake up that 300, but you probably won't see any improvement in fuel mileage. While the intake and headers will allow more airflow and thus a greater fuel requirement, if the skinny pedal is treated with a light touch it shouldn't impact your mileage adversely. It all comes down to combustion efficiency, and this won't change that. You'll be able to burn more fuel and make more power, but with essentially the same degree of efficiency.

With more power you can look at regearing, though, and that will get you some significant gains in fuel mileage. You didn't provide a lot of info regarding your trucks drivetrain, but an overdrive transmission and/or lower rear end gears can have a very positive impact on your mileage.

If I had stayed with the 300-I6 in my truck, I would have definitely gone with the offy intake and a 4 barrel carb, but then that's how I roll.

 

need to clarify this a little - gears with low numbers are counted as "high" or "tall". gears with big numbers are "low" or "deep" - i don't want the OP getting things backward there, the gears he would want are low-number, fairly high gears

 

Agree. Lower numerical gears to improve top end speed and fuel mileage.