I had a 1973 Ford LTD 429 in the late 1980’s. It was a speedster but also a slurper.
I had that same car. My dad gave it to me when I was 17 (in 1977). I had no idea why until I had to fill it with gas.
Not much on corners but on the straights it was a rocket on rails.
Then I bought a 1973 BMW 2002 and promptly rolled it the first weekend I had it.
My folks had a 74 LTD 4 door with a 400. That old Lincoln Trimmed Down could hold 100-110 no problem. The fuel gauge would drop even faster.