Best Muscle Cars

1969 Twin Turbo ‘Mule’ Camaro by Mark Stielow – The Birth Of Pro Touring

By FastMuscle | April 26, 2018

By Dave Ashton

VIN: 124379L520475
Engine: Twin Turbo SBC 389ci.
Transmission: 6 speed Viper
Exterior Color: Silver
Art Rasmussen subframe
Currie aluminum 9 inch rear end
custom 4-link rear suspension

This iconic 1969 Camaro was built by Mark Stielow (the manager of Program Engineering for General Motors) who arguably kicked off the Pro Touring term as we know it, along with Car Craft magazine’s Tech Editor Jeff Smith going back to the early 90’s. Apparently, the pro-touring term came from Jeff Smith asking Mark to come up with a name for the movement, so he borrowed the ‘Tour’ from the Power Tour of the time and ‘Pro’ from the Pro Street movement.

The ‘Mule’ naming came from GM’s lineage for naming a test model a ‘Mule’ for trying out new ideas with parts and bits coming from many vehicles. The term “Pro Touring” refers to a muscle car with upgraded parts such as suspension, brakes and drivetrain, while keeping the basic original external design of the vehicle.

The Mule was built in 2001, starting where the old leaf spring setup was replaced with a four link axle with coil over springs, Art Rasmussen subframe and a Currie aluminum 9-inch rear end. The engine comes in the form of a Chevy 389cid aluminum small block Twin Turbo producing 1,021hp at 6,800 rpm and 471 lb/ft. of torque at 6,800 rpm. This links up to a 6 speed Viper transmission. The interior features a very discreet roll cage, with the rest of the interior mostly left in stock condition, but with 5-point bucket seats and a custom gauge cluster. Lights on the tachometer light up when the driver needs to upshift.

Drive train upgrades included an intake manifold knob allowing the turbocharger boost to be reduced, allowing it to be run on 87 octane pump fuel.

The car even has its own book written and dedicated to the build of the machine by Mark Stielow and Will Handzel called ‘Pro Touring: engineered performance‘. Popular Hot Rodding Magazine covered the car’s build over 22 consecutive issues, giving you an idea of its importance. When the fifth-generation Camaros were being designed by GM, the Mule was parked in the studio for inspiration.

Here it is being sold at the Barrett Jackson auction in 2014 for an eye watering $198,000.

Another link is to Detroit speed’s website showing the Mule being worked on and giving you a nice close and personal breakdown of the vehicle.

Mark has also built many other standout custom Camaros over the years, such was the ‘Tri-Tip’ featured in the One Lap of America in 1993, the ‘Red Devil’, ‘Jackass’, ‘Hellfire’ and ‘Mayhem.’

The beauty of Pro Tourers is that they are mainly based on pony cars and with a total of 842,731 first-generation Camaros built and absolutely tons of first-generation Mustangs still around, there are plenty of vehicles to get creative with and upgrade in any permutation you wish. The general love of vintage muscle car design with upgraded parts all round results in arguably the ideal mix of modern motoring.

The Mule is currently on display at the Audrain Auto Museum – http://audrainautomuseum.org/cars/1969-chevrolet-camaro-custom-2-door-hardtop/