Marc Christ
Brand Manager, Modified Mustangs & Fords
December 10, 2013
Photos By: Courtesy Of Moore Good Ink

Results—that’s how we judge people and things. When a hurricane tears through a city, we judge it by the documented speed of its winds, its size, and by how much damaged it caused, in billions of dollars. When an athlete is considered for his or her respective hall of fame, wins are tallied, and records are considered. Cars are no different. We evaluate and appraise them based on quarter-mile capabilities, top speed, and of course, horsepower.

Horsepower is quite possibly the single most important results-oriented number in hot-rodding. The only exception would be quarter-mile e.t.’s, but with the ease of access to engine and chassis dynos, horsepower is king. So when we decided the ’88 GT that we are building for SEMA would be naturally aspirated, we knew the engine had to be a brute—a big-cubed Windsor with a nasty cam and some kind of sexy twist. We found all of those in the Jon Kaase Racing Engines P-38.

If you missed Parts 1 and 2, here’s a recap. We decided on a 427ci Windsor configuration based on the Ford Racing Performance Parts Boss 351 block (PN M-6010-BOSS35195; $2,199). We turned to DSS Racing for one of its bad-boy rotating assemblies, complete with a 4340 forged crankshaft, forged H-beam rods, and its top-of-the-line GSX forged pistons notched specifically for our P-38 heads. We hauled everything to Jon Kaase Racing Engines (JKRE) in Winder, Georgia; there Chuck Lawrence measured, balanced, and assembled the short-block.

So here we are with most of the hard work (well at least the precision work) behind us, only a few parts left on the bench, and saliva pooling in our mouths, as we can almost taste the bitter exhaust fumes. When we arrived at the shop, Lawrence had already installed the Comp Cams camshaft (0.678/0.659-inch lift, 303/315 degrees duration at 0.050, and a 106-degree LSA), timing cover, water pump, and Innovators West balancer and timing pointer.

Lawrence grabbed a pair of P-38 heads off the shelf and fastened them to our short-block using ARP studs and Fel-pro gaskets. He then measured for pushrod length to ensure proper valve operation. While waiting on pushrods, he installed the high-volume oil pump and pickup, and measured for proper pickup tube clearance; then he installed the Moroso oil pan and fastened it with ARP hardware.

Back up top, with pushrods in hand, Lawrence installed the guideplates, Comp Cams hydraulic-roller lifters and pushrods, the Crane Cams 1.7 rockers, and special P-38 valve covers. We opted for the aluminum sheetmetal version to fit our theme, but you can get cast-aluminum and leave them natural or powdercoat them to match your car’s paint or engine bay.

With Joe Gibbs Driven Oil in the crankcase, Lawrence primed the oiling system. He then installed the cross-ram intake manifold. Before we could run it on the dyno, though, we had to figure out a way to supply crankshaft and camshaft signals to our FAST system, and a way to drive the oil pump driveshaft. The answer came by way of an AEM Electronics ignition position module (PN 30-3253; $332.50).

On the dyno, Lawrence dialed in the tune for the FAST, and after a few pulls, the 427 screamed to 601 horsepower at 5,600 rpm and 614 lb-ft of torque at 4,700 rpm. It makes over 500 horsepower over 4,500 rpm, and over 500 lb-ft of torque until 6,100 rpm. This thing is certainly a torque monster, as we expected. To see video of our 427 on the dyno, go to www.musclemustangfastfords.com.

Next month, we’ll wrap up our paint job, and then it’s time for assembly. As we wrap up this installment, we’re only six short weeks from the unveiling of Hypersilver at SEMA. We have a lot of work to do, but by the time you read this, SEMA has been over for a few weeks. So go to our Facebook page to see the finished product.

1. Last time we visited JKRE, engine builder Chuck Lawrence assembled the short-block using a top-shelf DSS kit consisting of forged pistons, H-beam rods, and a forged crankshaft.
2. Lawrence had to notch the oil pump slightly to clear the counterweight on the crankshaft.
3. Here, Lawrence had already installed the Comp Cams camshaft and timing chain, as well as the timing cover, water pump, and balancer. The cam (0.678/0.659-inch lift, 303/315 degrees duration at 0.050, and a 106-degree LSA) was chosen specifically for our project, and ground by Comp.
4. The DSS Racing rotating assembly is available with multiple piston notching configurations, depending on your cylinder head choice, and ours was no exception. Just inform DSS that you’re planning on running the P-38s.
5. Innovators West supplied the balancer and timing pointer.
6. Here’s a last look at our P-38 heads before they’re installed. In case you forgot, these beasts feature 240cc intake runners and a canted valve configuration. We mentioned in Part 1 of this series that they require a specific intake manifold, but we were wrong. Any intake that fits SBF engines will fit the P-38s.
7. Lawrence installed Fel-pro gaskets and installed the cylinder heads.
8. We chose ½-inch ARP head studs.
9. He then torqued the ARP head studs to spec.
10. Lawrence then measured the oil pickup tube depth before installing the oil pan and adjusted the pickup tube accordingly.