I toyed with this idea for a long time maybe using a flattop LS1 Piston with probably an maybe an offset ground crank and 2" rod journals and the Late 302 heads and a ported SP2P (dual plane with isolated near equal length runners) intake with a tremec. Small tube shorty headers and a single 3" exhaust with a flowmaster Y pipe. Late model roller block probably a reground stock cam for more lift.

With the right gear in a semi aerodynamic car like a late 80's Chrysler Conquest (easy v8 swap my buddy has one) I was going to shoot for easy 30's on the highway. Build a broad torque curve with decent power and high manifold vacuum at cruise speed for efficient burn.

I had a 94 Firehawk LT1 that ran in the 13's stock and would cruise on the highway at 70 MPH barely ticking over 1700 RPM and 31 MPG.