The Duster has frequently been looked upon as the redheaded stepchild of the Mopar world. Introduced in 1970-near the end of the musclecar era-it was given a few performance options based on the 340 engine, but it never had the cubic guts or rugged good looks of its muscular big brothers.
Jeff Delzer, a self-proclaimed "Mopar freak," was born into a hard-core Mopar family. His dad worked for a Dodge dealer and often brought home Hemi cars, even owning a '6411/42 factory race Hemi at one time. When Jeff came across this '73 Duster five years ago, he thought it would be the perfect first Mopar for his 15-year-old son. The car was brown with factory stripes and a numbers-matching 340. It was complete, but it needed a right quarter-panel and quarter-window. The transmission slipped a little and there was a nitrous bottle in the trunk. Jeff dropped $1,500 in the owner's hand and drove the Duster home.
He immediately pulled the trans to get it in working shape. After looking at the engine hanging by the mounts, he figured it wouldn't be too much of a job to pull it out and throw on a new pan gasket and rear main seal as well. "That's when things got ugly," Jeff says. The previous owner had rebuilt the engine using inexpensive cast pistons. The added horsepower from the nitrous hammered the snot out of the cheap slugs, and Jeff found a few pieces of ring land in the pan. At this point, he decided to build one "bad-ass" small-block, cranking out 500-600 hp.
Jeff took the engine to Jobber Machine in Anaheim, California, where the block was cleaned, inspected, decked, line-honed, and bored .040 over with torque plates. TRW 10.5:1 pistons, a Milodon fixed idler-gear cam-drive, a 7-quart Milodon deep-sump oil pan, and a Herbert roller cam were added. Everything was buttoned up with ARP fasteners. Jeff had a set of fully ported and polished X-heads with Manley severe-duty stainless valves, Crane springs, and titanium retainers ready to add to the stout short-block. While he wanted to add aluminum heads, they weren't in the budget. This is where Jeff's father stepped in, ponying up the cash for a set of Edelbrock aluminum heads. All the components that had been added to the X-heads were removed and fitted to the new Edelbrock heads by Van Dyne Engineering. In addition, a custom set of Manton pushrods were ordered along with a set of Crane roller rockers.
Jeff added a Mopar M1 intake manifold that he port-matched to the heads, and a Sean Murphy custom-built, 4150 Holley 750 carburetor was bolted to the top. To supply the fuel, a MagnaFlow 275 pump and regulator was attached with a full set of steel-braided hoses and AN fittings. To ignite the mixture, an MSD ignition was used with the Digital 6AL box. TTI ceramic and thermal-barrier coated headers and a full 3-inch exhaust with stainless tips were added. A 727 TorqueFlite was built by Tim Deal using a B&M manual valvebody, a Hughes 3,500-rpm stall converter, and a Strange driveshaft hooked to an 831/44 rearend with a 4:10 Sure Grip spinning Moser axles. To beef up the rear suspension, Mopar Performance Super Stock leaf springs were added, along with drag shocks and an MP pinion snubber. The front end was also rebuilt, with heavy-duty torsion bars and urethane bushings. The K-frame and suspension components were powdercoated. To stiffen up the body, Jeff added subframe connectors. Since stance is everything in a car, this Duster has it up the wazoo. It rolls on 17-inch Stockton Torque Thrust wheels with Bridgestone 25/45/ZR17s up front and 255/50/ZR17s out back.