1988 Ford Mustang Boss 302 Crate Engine Boss 302 Engine
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.