Are 340’s rare

In late summer of 1970, I bought a slightly used Swinger 340/4-speed/3.55s. It was totally stock.
That car, the following summer, on the E70-14 polyglass tires ran a best of 14.4 at 98 mph; spinning those crappy tires thru two gears, at least.
It wasn't the fastest nor the quickest 340 at the track, but I got a trophy that day for being the fastest/quickest in my class.
Back in High School, it was the car to beat on the street, and I feared nothing, at least up to 85 mph, lol.