MPG? WTF's that? It gets empty, fill 'er back up.
Thats what I say. Its a hot rod. You want gas mileage get a diesel Rabbit. Mine is 350 Chevy, 6-71 blower, 2 650 HP Holleys, TH400 trans , full manual, 3300 stall, 4,30 gears, and 10 gallon gas tank. I can get about 8 mpg if I am careful on the highway. But usually on a Sat night cruise I get about 3-5 mpg.
Our blown bucket is very close to this.
We had a tub a few years back that would get 22-23 mpg. It had a 383 stroker with a mild cam and 750 Demon carb. The good gas mileage came from the 700R4 trans. It had a 2300 stall converter that would lock above 45 mph. So if you went on a cruise and kept the converter locked it did great.