Ford's Newest 302 Crate Engine - The Boss Is Back

The first intake we tested was the Weiand Action Plus street intake. It is a low-rise dual-plane design, has been around for about two years, and is the least expensive of the three intakes we tested. It is designed to operate from idle to 5,500 rpm and provide plenty of usable torque and vacuum signal for the carburetor to ensure hiccup-free throttle response. After three runs, the average peak was 345.5 hp at 6,100 and 332.3 lb-ft at 4,300. Those are the exact numbers advertised by Ford. Notice the bag of hardware that includes the pipe plugs-you never see that anymore.

We've often pulled the single-plane out of the hat for a big, glorious dyno number to print on the cover. Single-planes deliver the air/fuel mixture using a common plenum and short runners that kill the low-end torque provided by a long runner and add high-rpm horsepower by increasing the velocity of the mix entering the port. The bigger the engine and the more rpm, the better. In this case, the Weiand X-Celerator averaged 342.8 hp at 6,000 rpm and 332.3 at 4,300 rpm. As predicted, the small displacement and cam produced a number slightly shy of both the Action Plus and the Stealth.

The second intake was the Weiand Stealth. It also has a dual-plane design but uses a high-rise plenum for a little more airflow required by a larger engine. The theory goes that a small plenum is better for a small engine and vice versa. If the plenum is too large, the engine will not perform well at low rpm. A small plenum on a large engine creates reversion and disrupts the engine at high rpm. The Stealth had an average peak of 343.2 hp at 6,300 rpm and 327.7 lb-ft at 4,500 rpm, slightly shy of the Action Plus number.

But wait! There's more! Ford also has a Boss 347 that uses the same internals with the addition of the Ford Racing aluminum Z heads, Victor Jr. intake, an MSD distributor, and a 9.7:1 compression ratio. The advertised horsepower rating is 450 at 6,000 rpm, but it costs $2,300 more.

What Did We Learn?
As you can see by the dyno curves, the Action Plus made more average torque and horsepower until the curves crossed at 5,250 and the X-Celerator began making power. The problem is, the cam and heads begin to run out of breath about this time and the single-plane falls on its face. The Stealth has trouble in the midrange but begins to pull hard near the 6,000-rpm redline, even surpassing the Action Plus at the top before it too runs out of air. If we had more cam duration and a larger, better-flowing cylinder head, we would have seen the Stealth take over near torque peak and finish ahead of the Action Plus. If we had a lot more cam and cylinder head, we could have spun the engine higher, and the X-Celerator would have had a better peak horsepower number. For the Boss 302 with warranty parts, we recommend using the Action Plus.