Getting ready to rebiuld the 302 in my truck. Nothing fancy, just forged pistons, fairly low compression, good rod bolts, a slight cleanup on the factory heads, 260 Compcams High Energy cam, MSD ignition, and little else save for headers and 2.5" exhaust.

I want to use a old B&M supercharger (about 4-71 sized) and I'm hoping to keep getting about 19.1mpg (or more) with some added power, esp while towing.

The truck is just a old 1979 Ford F100 shortbed stepside (Free Wheelin') with the 302, SROD, and 3.00 gears. I'm not touching the rest of the driveline as I want to keep the good milage and have it as factory as possible (within reason).

The gameplan is to get the power of a decent 460 (when needed) while having the economy of the 302.

 

If you are going to keep the stock heads then I would recommend a port job...at least on the exhaust side. They are very restrictive for boosted applications.

Also, "supercharger" and "good fuel economy" should never be used in the same sentance.

 

I figure if I keep off the boost, it should do pretty good. As far as the stock heads are concerned, they will be getting a mild cleanup (mostly on the exhaust side) and polished chambers, but little else will be done (stock valves, ect... for now).

I might go aftermarket on a later date, but again, it's not going to be the ultimate powerhouse, otherwise I'd build a bigger engine.

 

Yeah, that's what I said with my first S/C'er build. I could go on and tell you how it has progressed since then, but I'll just say that you will be addicted the first time you nail it.

 

All the boosted vehicles I've owned, driven, and towed with generally got better mileage than the na variations.

 

I've never really tracked my fuel milage...I just can't keep my foot out it most times.
Of course, three fuel pumps and 42lb squirters (soon to be 50's) don't help the fuel economy at all, but it does make for a safer tune.