One of the biggest challenges that RPM faced was fitting the massive Jon Kaase-built Boss Hemi engine in the car. To maintain the look and design of a Mustang, they wanted to leave the shock towers in place, but the engine was 3 inches wider than the shock towers. RPM cut out the reproduction towers and fabricated new ones further out to make room. In fact, the sheetmetal underhood was custom made for a clean look, right down to the air filter housing. For strut supports, RPM started with a set of Ringbrothers pieces and modified them to fit the heavily modified engine bay dimensions. They also milled the motor plates from 1/2-inch billet aluminum. One of the few things they didn't fabricate was the Billet Specialties front drive system for the engine. RPM moved the firewall back nearly 4 inches to set the engine back in the chassis for better weight distribution. This is the type of custom work that you rarely see on a giveaway car. This shift in weight along with hundreds of other changes resulted in weight distribution of 1,000 pounds on each wheel. It doesn't get any better than that!
For a novice, a casual glance...
For a novice, a casual glance underhood the Boss Snake reveals a nice engine bay that's very well detailed. A Mustang enthusiast quickly picks up on all of the changes, including shock towers that have been shrunk and moved outboard, a custom firewall further back in the car than factory, and a one-of-none fabricated air cleaner.
The engine itself is also a masterpiece. The original plan called for a Boss Hemi, but just a little bit better than a passenger car Boss Hemi would have been. Sounds great, but then they called on Kaase Racing Engines for the motor, and Kaase doesn't do anything a little bit better than anything. He figured the best motor for this thing would be a 520 that produces lots of low-end torque and doesn't require a lot of rpm to make a ton of horsepower. Kaase reminded us of what unique pieces of machinery the original Boss Hemi 429s were. They required a lot of specialty tools, parts, and knowledge to build. But they are also one of the most drool-worthy Ford motors ever engineered. Kaase created the Boss '9 heads and intake, and rearranged how the parts are made so you can use a production 460 block and build it yourself in your garage with normal tools. Kaase selected a COMP Cams hydraulic roller camshaft for this specific engine for a virtually maintenance-free 771 hp and 501 lb-ft of torque. The rest of the drivetrain consists of a Tremec Magnum six-speed, Centerforce clutch, and a Currie 9-inch housing stuffed with 3.89 gears and 35-spline axles.
Ukasik and his team like to make sure that the cars they build perform as well as they look, so the construction of the chassis was extremely important. They started with Ridetech's ShockWave system and modified it to fit the one-off chassis. This combination allows a completely adjustable suspension for ride height and handling. With the Intro 18-inch wheels and BFGoodrich KDW2 tires, this car has an ultra-cool stance and head-turning cornering ability.
The interior was a blank slate. The Dynacorn bodies don't come with a dashboard, and there were no seats, door panels, or anything else. RPM formed a dashboard from sheetmetal that remained true to the style of a classic muscle car, but housed Classic Instruments gauges stenciled with "Goodguys Boss Snake," and a Clarion navigation system. Vintage Air climate control will keep the new owner of this car cool while jamming out to the Clarion/Kicker audio system and rowing gears on the Tremec. RPM also fabricated a center console and covered everything in black leather supplied by Finish Line Interior. The Mustang also features Ridetech's new Tiger Cage and safety harnesses.