Super Beast Mode: The Allis Chalmers 8550

Allis Chalmers was covering new ground during the 70s. The ground-breaking 7000 series was selling well, and they’d dipped their toes in the 4WD tractor market with the Steiger-built 440 earlier in the decade. Things were going well enough that in 1976, they unleashed “The Beast” – the 7580. It was AC’s first in-house 4WD tractor, and sported a bunch of nice improvements over the outgoing 440.

But…at 186 PTO horse, it was a little wussy for such a big tractor. Customers needed more.

In 1977, AC unleashed a badder animal…8550, known as The Super Beast. Where The Beast got its power from the 426, The Super Beast used one of the biggest motors Allis ever stuffed in a tractor. 731 ci of twin-turbo muscle, rated at 253 PTO horse! This tractor was literally so big that they had to disassemble part of it to get it into the Nebraska lab to test it!

This particular 8550 is a one-owner ’79 model with only 5342 hours, and it’s in GREAT shape for its age! Not only that, it still sees regular use on the farm! It lives in Indiana until Tuesday…then we’ll see where this big tractor ends up!

BTW: Funny story about another Super Beast…back in the day, AC had a strong marketing partnership with Loretta Lynn. They had a working hobby-type ranch in Tennessee, and farmed with orange tractors. Early one Sunday morning, one of the local dealers got a frantic call from Loretta’s husband Mooney. Apparently he’d learned that Super Beasts can’t swim. I believe the story goes that there’d been a little Saturday night drinking involved, and he’d driven it into a pond and cooked the motor in the process.

After a bit of “discussion” between the involved parties, Allis replaced the motor in that tractor, and it’s still working on a farm in Ohio today!

Super Beasts don’t come up for auction every day…but lots of other Allis Chalmers equipment does! Browse it all here!