Those old Ford side-valve V-8s were made in the millions, starting in, I recall, 1932. Chevrolet had been outselling Ford for several years by introducing a serious six-cylinder engine to challenge Ford's fairly pedestrian four-cylinder job. Some makers tried "straight-eights", but they were difficult to make, required a ludicrously long and thus fragile crank-shaft, and had "cooling issues".
Ford's response was the classic "flat-head" V-8. It was cheaper, more powerful, ran smoother, and with a few "custom parts" could be made to go VERY fast.
They were eventually superseded by an overhead-valve engine in 1955, again playing "catch-up" to GM who changed the game with their "small-block" OHV V-8.
The old "flat-heads" were made in the US and Canada, with little if any variation, for all those years, so, there should be a few parts around for the old Ford "flat-heads".