I think discussing gas milage is very important these days, especially to those of us who use our rods a lot, and on long trips.
My 23 got 25 mpg normally on a trip, and one time I even got 30 mpg coming back from Billetproof. It had a mild Vortec 350 Chevy and TH 350 trans, with 3:00 gears and tall slicks out back. At 60 mph I was just off of idle.
My 27 likes gas, especially around town. But I just averaged 20 mpg going to Daytona, which surprised me. It is a 331 Ford stroker, aluminum heads, Ford Racing X303 cam, Ford 3 speed stick, and 4:30 gears in the 9 inch rear. I was expecting much less, especially cranking 3000 rpms at 60 mph.
The secret to pulling good milage seems to be having a mild cam, one properly sized four barrel, an overdrive transmission, and some tall gears in back. Wind resistance and weight factor in too. My 23 was light and so low it had no wind resistance at all, which is why it sipped gas. Fuel injection and a computer would even give better numbers.
Don