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Big machinery is so sick. That’s why I’ve spent the last couple of years following The Mahan Collection’s Mack M100SX revival, as it’s the largest Mack truck ever made. Meanwhile, Welker Farms out in Montana has been restoring a 1977 Big Bud KT-450 and turning it into a custom Big Bud 700—one of the largest tractors ever made. It’s finally finished, and the rig is earning its keep during the 10,000-acre farm’s wheat harvest.
Now, notice that I said “one of the largest” and not just “the largest.” That title belongs to the Big Bud 747, which runs a Detroit Diesel 16V71 and stands 14 feet tall while measuring 25 feet wide. Still, Welker Farms’ newest Big Bud (it owns three) is plenty stout, weighing roughly 52,000 pounds full of fuel and without any ballast. It runs a 700-horsepower Cummins KTTA engine, having ditched the original 19-liter diesel for a compound-turbo unit that’s the same size, and it’s paired with an Allison 6000 Series transmission.
The Big Bud’s 75,000-pound Caterpillar axles are flanked by custom Wold wheels wrapped in gigantic Titan 1400 LSW tires. Its tires are so big, in fact, that the tractor’s original fenders had to be modified to fit. As you might expect, there’s a lot of custom work on this piece of equipment, seeing as there aren’t many new-old stock parts lying around for a low-volume tractor built in Montana during the 1970s.
Welker Farms via YouTube
Transforming the Big Bud from a naked frame to a functional tractor took roughly seven months—and a whole lotta money. Welker Farms put up $114,700 of its own cash, while sponsors contributed $104,900 worth of products to make it happen. They totaled 4,000 man-hours of work on the project, and if they’d paid a shop $150 an hour for labor, that would’ve totaled an additional $600,000. In all, if they had hired out the job to a professional shop, they would have forked over $820,000.
Having the biggest tractor out there was never the point in building this Big Bud 700. Instead, Welker Farms went through all this trouble to have a piece of history working on the property. It also benefits the farm by being easily serviceable, unlike a lot of modern equipment. And even though it’s still enormous, it won’t compact the soil nearly as much as a 747, and if something breaks, it shouldn’t be nearly as much to deal with.
The Return of 700HP Monster BIG BUD!!
There are currently three generations working on Welker Farms, and from the looks of it, this tractor will be around for a while, too.
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From running point on new car launch coverage to editing long-form features and reviews, Caleb does some of everything at The Drive. And he really, really loves trucks.
