The Story Of A 600 HP, Stock Bottom End 7.3L, Part 3
Dyno Numbers, Drag Racing, And Towing With A 25-Year-Old Ford
Ten years into our 600hp stock bottom end experiment, the 225,000-mile 7.3L Power Stroke in our ’97 F-350 keeps on ticking. To be sure, its horsepower recipe is extensive—and includes 350/200 hybrid injectors, an S400 turbo, and a billet internal transmission—but the factory rotating assembly is 100-percent as it was when it first left the assembly line back in the late ‘90s. The heads are untouched for the most part, too, their only upgrades being ARP head studs and stiffer valve springs.
Over the course of the last decade the truck has been subjected to dozens of dyno pulls and countless more passes at the drag strip—and it’s all been carefully documented. But while the immediate aftermath of the build meant the truck was often used for play, it continued to be a daily driver. In recent years, and primarily because the engine hasn’t let go or shown any signs of giving up, the OBS Ford has become a tow-rig above all else. You can usually find it hooked to a 10,000-pound toy hauler in the spring, summer, and early fall.
For the third and final installment of this series, we’re taking a look at the truck’s finest hour on the dyno and at the drag strip. Then we’ll highlight the upgrades we’ve made to improve its towing manners and theorize why we think the 7.3L has lasted so long at this power level. Whether the O.G. Power Stroke continues humming along for another 10 years or sends a rod through the block tomorrow is anyone’s guess, but given the trouble-free track-record it’s accumulated so far, we’re definitely not afraid to give it the chance.
Air Lift Company
John Wood Automotive
Power Hungry Performance
Unlimited Diesel Performance
ODOMETER: 225,172 miles
MILES AT 600 HP: 50,000 miles
MILES AT 500+ HP: 70,000 miles
MILES AT 350+ HP: 100,000 miles
BLOCK: Factory forged-steel crankshaft, forged-steel rods, forgedsteel camshaft, and cast-aluminum pistons
HEADS: Factory 2-valve cast-iron with ARP head studs Valvetrain Mods: Comp Cams 910 valve springs, Hamilton Cams chromoly pushrods
FUEL INJECTORS: Unlimited Diesel Performance 350/200 hybrids
High-Pressure Oil Pump: Stealth SRP1.1
FUEL SUPPLY SYSTEM: Irate Diesel Performance competition system with Fuelab Prodigy pump, regulated return, Bean Machine sump
TURBO: Irate Diesel Performance T4 turbo mounting kit, Fleece Performance Engineering S468/87/.90, Irate 3-inch downpipe and intake plenums, Driven Diesel overboost annihilator
EXHAUST: Diamond Eye Performance 3-inch downpipe to 5-inch no muffler system
TRANSMISSION: John Wood Automotive Street Performance E4OD with triple-disc, billet stator converter, Maraging 300 input shaft, 300M intermediate shaft, cryogenically treated output shaft, 4340 flex plate, Goerend pan, Mishimoto 5R110W cooler
Suspension: Factory replacement leaf springs, rear Air Lift air springs,
One Up Offroad traction bars