Small block mileage

What fresh hell have I awoken? Haven't had a 318 in many years, but we drove our cars differently when gas was $0.39 a gallon. Yes, on that freaking old. Anyway, I appreciate all the info. Was just trying to decide what motor to put in an a body to get the best mileage and still have enough grunt for when I go up into the Rockies.
Slant 6
LOL No 'fresh hell". It is just one of our favorite topics. It' up there with "which cam should I put in my 360", "what are the best spark plugs to use" and "why won't my car start?" The way I see it, there are three camps on this fuel mileage thing. 1) Who cares what the gas mileage is. Just drive your classic car and enjoy it; 2) I love squeezing every MPG I can get from my ride; and 3) I want a classic car with a powerful motor that gets at least decent gas mileage.
I hover between 1 and 2. I do not worry too much about mileage. I get about 10 in town and about 15 on the highway in a 69 Barracuda with modified 340, 3.55 gears and a 4 speed. I am fine with that. Now that being said, if my mileage dropped to 5 in town and 10 on the highway, I'd be looking for the culprit. Adjusted for inflation, there isn't really that much difference between gas cost now and when I was going to college. in 1969-73, I was paying about $0.40 per gallon and earned about $7,000 per year. That equates to working 6.86 minutes to buy a gallon of gas. If you are working today and earning $80K per year with gas at $4.50, you are working 6.50 minutes to buy a gallon of gas. You could ALMOST say that it all comes out in the wash. My main comment is that I certainly understand if you are getting atrocious mileage due to a mechanical defect, then by all means solve that problem. But if you are getting a mileage number that most of us say is about right, then go with the flow.
call me when you pay $8.00 a gallon for gas , you'll care or you have very deep pockets with toilet paper rolls of $100.00 bills