Let's say you own a '71 Demon. This Demon can go to the store for groceries, spend a Sunday afternoon on any show field, drive to the local quarter-mile track, race, and drive you back home. Would you call this car a true streetcar? What if this car is capable of covering that quarter-mile in less than 10 seconds? Is it still a streetcar?
Ron Silva of Alta Loma, California, calls his Demon just that, because it does all of the above. Ron, a control operator at a powerplant-yep, he's a real-life Homer Simpson-bought this demon of an A-Body eight years ago for the sum of $550.
It all started when he placed a want ad for a Demon in a local auto paper. The guy who answered Ron's ad had gained possession of a Demon by sneaking in and buying it out from under Ron sometime earlier. Now, Ron was finally able to get it. The car was factory supplied with a Slant Six.
"I have had many cars and wanted to build a fast, dual-purpose, understated street car that could run a very respectable number at the dragstrip," says Ron. "It had to be street-driven so I could just drive it to the local drag events at Fontana and Irwindale and all the various car shows and cruise nights. Trailering/towing a car is too much work!" For the first couple years, he ran it with a 380-horse 360 crate engine. He would drive it, race it, and just plain enjoy it. Then one day, Ron was bitten by a bug-the racing bug. His bug required his car to go a lot quicker. Admit it, we've all been there.
The stock unibody construction was stiffened with owner-fabricated and installed frame ties made of 2x3-inch, .125-inch-thick mild steel tubing. Ron also installed the Art Morrison rollbar himself, sending the back bars over the seat and through the rear deck, thereby allowing the rear seat to be reinstalled. When it came time to handle bodywork and paint, Ron found Lloyd's Auto Body in Ontario, California. He'd met Lloyd years earlier while street racing and knew he was the guy to cover the Demon in a smooth-as-glass shade of '95 Ford Spectramaster Blue Metallic.
The Mopar Performance aluminum carrier was mounted into an 831/44 rearend housing from a '70 Dart. The center was filled with a Detroit Locker spinning 3.91 gears and Mark Williams axles. The assembly was supported by Mopar Performance Super Stock springs that were moved in 31/44 inch with a Polygraphite bushing in the front spring eyes and HAL adjustable long drag shocks. Up front, Polygraphite bushings were installed in the stock control arms, and Mopar Performance race torsion bars support the weight. Koni SPA-1 Drag shocks help with the 60-foot times, and Wilwood brakes on all four corners ensure the combination of Mickey Thompson/Hoosier Quick Time Pro tires get her whoa'd before the track ends.
Because Ron originally planned to primarily street-race this car (is that legal in California?), he wanted the interior to look as close to stock as possible but also be as light as possible; take, for example, the fully-upholstered JAZ lightweight front seats, full-size back seat, new door and rear interior panels, factory original radio, and heater-delete plates. The seats were skinned by Raule's in Ontario, California, with material from Legendary Auto Interiors. The six-point rollbar was painted to match the other interior panels to help conceal it. Notice the absence of a tachometer? Ron wired an adjustable rpm switch from his MSD ignition that turns on the original brake system "idiot light" in the dash as a shift light. He says this works better than you may think. Since there is a radio delete plate in the dash, what does Ron do for cruisin' muzak? Let's just say the 700 horses under the fiberglass hood are music to the ears.
Speaking of Ron's music maker, the engine started life as a Mopar Performance 340 R-3 block that was clearanced for the rods and stroker crank. The main caps were cut, and the main journals were line-honed using a BHJ torque plate, and drilled to accept pushrod oiling. Ron spent two days in his driveway lightening the block with hand tools. A billet steel Kryptonite crankshaft by LA Enterprises displaces a 4.375-inch stroke and has 2.100-inch rod journals. The crank weighs a mere 50 pounds. The CP custom pistons are connected to the crank via Manley Pro Series lightweight rods, 6.300 inches long. The Comp Cams camshaft sports .630-inch lift and a split .262/.266 duration at .050. MP W-9 aluminum heads pull the fuel from the Barry Grant Race Demon carb through an MP intake matching the W-9 heads. Total compression ratio is a streetable 11.5:1. An MSD billet aluminum distributor, an MSD crank trigger with a shielded pickup wire, and an MSD digital 6 ignition control provide the spark. Timing is locked at 29 degrees total. To enhance traction, Ron sometimes uses a 12-volt DC analog adjustable timer to pull out 9.9 degrees of timing from the engine during launch via the digital 6. The final product displaces 474 ci.
When it came time for headers, Ron faced a dilemma-nobody made headers for a W-9-headed A-Body Mopar. His solution: build them himself in his garage. He began by getting all the necessary pieces from Specialty Designed Products in Rancho Cordova, California. The header tubes are stepped from 171/48 inches to 211/48 inches, ending at a pair of 211/48-inch to 3-inch merged collectors. Once he had the headers built, they were Jet-Hot coated. From there, the fumes pass through 3-inch Walker Dynomax Super Turbo mufflers out back.
A 904 TorqueFlite, built by Pro Trans in Lancaster, California, handles shifting duties. They filled it with a 10-inch Turbo Action torque converter, giving an approximate stall of 3,800 rpm and a Pro Trans-built reverse manual valvebody.
So what did all these parts do for Ron at an altitude of 2,400 feet during the Mopars at the Strip show in Las Vegas? The Demon turned a best time of 9.95 at 133.69 mph, and Ron had to slow the car down in order to pass tech. Keep in mind this was accomplished with a full interior, a small-block engine, and rear tires that are only 11.5 inches wide. The highway crown is claimed!