Need help deciding on a 360

I'd be perfectly willing to give up the rumpidy, to gain a 400ftlb plus engine with a big fat long torque curve, the gets mileage like a sweet teener.
I'd like to drive to Calgary, or some other exotic western city,lol, run up the track a time or two,post say a mid-eleven,and upon returning home, find that I averaged 25mpg or better! And the nice quiet ride would be a welcome bonus. Jus saying.....