The N-series Fords were made for about a zillion years - from about 1937 or so, until 1953 and were, at one time, the single most popular tractor out there.
There were a lot of engine conversions "back in the day" as well as different transmissions put in them. Later there were a lot of conversions using other engines, ranging from OHV fours to big block Ford & Chev engines.
There was near-identical one produced by Ferguson and a British version as well with Rover power. Some were also disease-el powered. (Ferguson invented the 3 point hitch, which Ford used, leading to a "handshake agreement" on production, which Ford later arbitrarily "tore up")
By the standards of tractors, they were too small, too light, too (this that & the other thing) - there were much better tractors available, but they all cost at least twice as much, so the N-series, produced with a flathead Four, sold by the trainload.
This one, with a flattie V8 conversion was not all that unusual as conversions go, although very few conversions would have gotten headers! Most stayed stock and worked their lives out - first as a farm's one and only tractor, then as a second, lighter work machine when one capable of pulling a much bigger plow was purchased, then relegated to pulling the hay wagon, then eventually just getting parked down back by the fenceline.