To go along with the new engine, Scofield added Weld AlumaStar 2.0s up front, and sent his existing RTS rears back to Weld for beadlocks. He also added a Cervini’s Auto Designs cowl hood to give the car a more menacing look. Photo courtesy of Tyler Scofield.

Jeff Scofield is not one to do anything slow. He’s owned the gamut of performance cars, but this 2014 Shelby GT500 has shown to have staying power. Scofield started with usual upgrades like a Kenne Bell 3.6LC supercharger, and intake and exhaust improvements. With a little nitrous thrown in the mix, the car made really good power.

However, the stock engine’s oil pump gears gave out while running down GTRs, which necessitated a redo. Progressive Racing Engines redid the short block, and the stock heads went back on with Comp Cams Stage 3 camshafts. The Kenne Bell 3.6LC was discarded in favor of the company’s big dog 4.7L supercharger, and with 28 pounds of boost the combination was good for over 1,000-rwhp.

At the 2015 Mustang Week, mechanical damage once again reared its ugly head with a broken rod. He noticed the engine wasn’t running right after a couple days into the event, and thought he had addressed the car’s issues with a new mass air meter. It appears, though, the damage was already set in stone, and during “spirited driving,” a connecting rod let go.

Amazingly, the engine still ran enough to get him back to home base at Mustang Week, and he was able to trailer the car home to assess the damage. The block was fine, but the broken rod, and subsequent thrashing around of components took out a couple cylinders, which brought Scofield back to the drawing board once again.

Mustang Performance Racing’s Tim Eichorn and crew whipped up a 364-inch engine using a Sonny Bryant crank, Manley I-beam rods, and Diamond pistons. The headers were ported by Kris Starnes, and Bullet Racing cams were set in place before the newly-powdercoated cam covers were reinstalled. The Kenne Bell 4.7L supercharger sits atop the combo with a Mammoth intake. “This is the baddest modular engine I’ve ever built,” MPR’s Eichorn says.

Progressive Racing Engines did a great job on the first engine, and the broken rod was nothing they could have predicted. However, the second time around Scofield went to Tim Eichorn at Mustang Performance Racing (MPR) for the engine build. Eichorn is one of the premier engine builders in the Ford market, and with modular engines, as well.

Eichorn and Scofield put their heads together on what Eichorn says is the “baddest modular engine I’ve ever built.” Scofield gave Eichorn free reign on the build, and wanted the best of the best. To that end, the short block was treated to Darton sleeves, a Sonny Bryant 4.350 stroke crankshaft, Manley I-beam connecting rods, Diamond pistons, Total Seal rings with a steel ring upgrade, Clevite coated bearings, and Cometic custom MLX head gaskets.

Up until this iteration, the heads had remained stock, but that changed when Eichorn sent the heads to Kris Starnes for full porting, bronze valve guides, a custom MPR valve spring and retainer kit, and Ferrea valves. Once back at MPR, Bullet Racing Cams grinds were set in place with a Cloyes billet steel secondary gear and chain kit, and Accufab secondary tensioners. The engine’s existing Big Gun intercooler was ported, as well, before going back underneath the Kenne Bell 4.7L supercharger.

Scofield arrived at MPR’s Boynton Beach, FL’s headquarters 5 minutes before the engine was done, immediately returning home to get started with the redo. It only took a couple days to have the car running under its own power, but he had to put some miles on the car to help break in the new engine and the car’s new McLeod clutch before taking it to Coastal Dyno to see the fruits of his labor.

Unfortunately, when that day came, Coastal’s Sam Lippencott noticed something was amiss. The engine was sucking air somewhere after the blower. Therefore, the day that was supposed to be dedicated to dyno tuning the new engine was spent chasing parts. The source of the leak was never truly found, but the next day the engine’s intake gaskets were replaced, the oxygen sensor that threw the code was replaced, and everything was put back together.

Numbers don’t lie. On Coastal Dyno’s Mustang Dyno, Scofield’s Shelby put down 1,176 corrected horsepower. He’s hoping to run in the 8s once the Florida weather cools down (If it ever does), then he might switch to an automatic to really see what the Shelby has in it. Of course, since the Shelby is a street car, the auto won’t stay in the car very long.

Lippencott slowly crept up on the tune, but with the larger cubic inches, ported heads, and revised cams, the combination was more efficient than before. With the previous engine with the same Kenne Bell 4.7L supercharger, boost was at 28 pounds with a 4-inch pulley. With the new MPR engine, and ported heads, that number was now down to 23 pounds with a 4-inch pulley. Scofield had a 3.75-inch pulley with him so that was put on once Lippencott had more of a handle fuel and timing needs. With the 3.75-inch pulley, boost was up to 24.5 pounds, and tuning with that pulley on it, the combo made 1,176-rwhp.

Of course, the MPR engine is capable of handling more, and Scofield was pleased with 1,175-rwhp, but he knows the engine will handle more boost, so more boost it will get. Scofield is researching smaller blower pulleys to get the combo back up to the 28 pounds of boost area. Plus, Scofield is hoping for cooler air when he returns to Coastal, as well. The previous day at the dyno it was 94 degrees, which wasn’t helping horsepower production.

When he returns to Coastal with a smaller pulley, and hopefully, cooler temps, he’s looking for 1,250-rwhp. We’ll let you know if that comes true. He is also contemplating a switch from Gulf 116, which is what was in the tank for the 1,176-rwhp, to either E85, or even E100 to see if there’s a power improvement. “I don’t want to leave anything on the table,” Scofield says.