51hp Head Swap To the Wheels

It's crucial to have a clean sealing surface before laying down the new head gaskets. While an air tool certainly speeds up the process, a gasket scraper will suffice.

Trick Flow's aluminum Twisted Wedge heads are far superior to the factory counterparts. The valve angles are rotated to unshroud the valves and the spark plug has been moved closer to the center of the cylinder. This unique design also allows the large 2.02-inch intake valves to clear the notches in the stock pistons without having to fly-cut the pistons. Ingenious!

We opted for ARP studs over standard head bolts because we intend to hit the motor with that same 150hp shot of NX nitrous in the future. The studs will not stretch over time like conventional bolts, providing additional clamping force that makes up for the Ford's limited number of head bolts (10 versus 17 on a small-block Chevy). We applied ARP thread sealer to the lower studs, since they're exposed to the heads' water jackets.

When laying down the new head gaskets, make sure you can see the inscribed words "front" facing toward the radiator. Not doing so will block coolant passages and could potentially cause the motor to run hotter than normal. Hey, it happens and we've seen it.

Mounting the heads with ARP studs wasn't a problem on the passenger side, however the driver side can pose a minor problem with the large brake booster that causes a clearance issue. The trick is to thread in the upper studs after mounting the head. That's it.

Before you torque down the heads, place a liberal amount of moly lube on both the thread of the stud and at the base where the washer is (arrow) to ensure accurate readings when you torque the heads. We torqued each bolt in three steps starting at 35 ft-lb, then 50 ft-lb, and finally to 70 ft-lb (see chart for torque sequence).

Up top we replaced the original stamped-steel rockers with a set of TFS's aluminum 1.6:1 roller rockers (right). These trick units feature heat-treated CNC-machined bodies, premium needle-bearing fulcrums, and a machined relief for improved valvespring clearance, and come complete with poly locks. The pushrods were also replaced with a set of TFS chrome-moly pushrods that measure out to 6.750 inches for proper valvetrain geometry.

After the lower and upper manifold was replaced, we drained the old oil and filled the motor with a fresh batch of 20W-50 Castrol GTX. If it's good enough for John Force's Mustang, it's more than adequate for ours!

At the track, we used a set of P245/50R16 Nitto NT-555R Extreme Drag Radials for added traction. Tire pressure was dropped to 15 psi. We did a healthy five-second burnout and dropped our 60-foot times from a traction-limited 2.5 to a much quicker 2.1. We also like the fact that the Nittos handled very well in both wet and dry road conditions, which makes them very driver-friendly for everyday use.

The proof is always in the numbers, and the Morgan Motorsports chassis dyno revealed an awesome gain of 51 hp and 45 lb-ft of torque from a simple head swap!