Maybe so, but compare the weight of the vehicles then and now. They outweighed the new cars by 3:1. That makes your 5 second car a 15 second car...
Please don't think I am picking on you. I am just not agreeing with this statement. It is popular to believe cars today are lighter built and yes many are but many are not. Modern automobiles can be as heavy or heavier and yet many have increadible acceleration. My Tundra 4X4 is pretty chunky but it will embarrass many cars old and new when it comes to acceleration, 0-60 in under 8 seconds, curb weight 4,700 lbs. Most personal vehicles weigh between 3,000 and 6,000 lbs depending on what exactly it is, then and now. The Viper is an example of torque and horsepower combined with a fairly light chassis. Some of the big Chevy and Ford PU trucks are examples of 6,000 lb vehilces (or close) that have huge power and darn impressive acceleration. The Kawasaki Z1000, 0-60 in 3.15 seconds, 493 lbs wet. Dodge Viper, Corvette, Porche and several fairly mundane cars can easily go under 6 and even 5 seconds. My 3,500 lb Mustang SVO, 1986, would do about 5.5 seconds, it was not stock but not wild either. It was also a 4 cylinder. On a dyno it pulled 275 horses at 19 psi boost. I put 65,000 miles on that car trouble free--mostly--- and sold it to a guy down the street (back home) who collected cars. He still has it.
Anyway, I just like talking about vehicles--sorry---in a way horsepower relates to torque like voltage relates to amperage. One without the other is useless. The good old 8N was wisely designed with it's large displacement engine which makes plenty of torque avaialbe. I bet it has a very broad power range also. J