Yes, a tractor.
Southeast Farm Press. He broke the record at a mile-long landing strip in Wilmington, Ohio.
Donohue's shop replaced the engine with a flathead eight-cylinder engine in part because that engine was available as an option on Ford 8N tractors in the early '50s. Donohue's shop made further tweaks, including changing the gearing, and others that doubled the engine's horsepower from 100 to about 200.
The biggest challenge the tractor posed for the shop was the need to make adjustments to its steering, so that it could be handled at such a high speed.
In doing so, Donohue rocketed past a record speed of just more than 67 mph, set in 1935 by David Abbott "Ab" Jenkins at the famous Bonneville Salt Flats in Utah.
Despite eclipsing Jenkin's record, Donohue calls him "Superman" and a "land speed guru," who still holds many records almost 60 years after his death.
"That's how far advanced he was. The tractor record is only one of the many records he still holds," Donohue said. "I was fortunate enough to get one of his records, but boy, that guy is an icon."
With a few more tweaks, Donohue believes his tractor can break 100 mph.
The team plans to take the tractor to the Bonneville Salt Flats and to land speed events around the country.
Donohue told CNBC that his shop is also working on a NASCAR-like stock car they aim to use to break land speed records for stock cars.
"The stock cars at Bonneville, off-the-trailer, probably run anywhere from 200 to 230 miles an hour," he said. "And we feel the car we have will do 250 plus. So that will give us a record with a stock car. Of course the goal is 300 mph. We don't know if we'll get that far, but we'll try — 300 with a stock car would be pretty neat."