any body building a mopar for max mpg?

My 65 will be somewhat MPG oriented when it gets redone. I get 22 MPG with the worn out slant and would like to keep fairly close to that with the 318.

Here's the plan so far:

KB167 pistons @zero deck
302 heads, 1.88/1.60 valves, mild port and polish
Hughes HEH 1523 cam
Headers (Spitfire or similar), 2 1/4" down tubes into a 3" single exhaust.
904 with low gear set
3.23 gears

Sounds pretty mild right? I want a responsive efficient little V8, with a similar power curve to the old HP 273. I want an engine that will not hurt itself and that is capable of going 100,000 miles between major maintenance.

Sure I could go faster, but I drive this car to work on the freeway daily. And I have 2 teenagers that will be driving the car as well. I'll go looking for something else for a pure bracket basher.