http://www.gmhightechperformance.com/ ... _cylinder_heads/dart.html

[QUOTE]Cylinder Head Testing - LS2 Dyno Thrash Part II: Head Shootout
The Dart heads are a bit of a mystery to us. They appear to be very basic, as-cast aluminum heads for an LS1 engine. That, you would think, would hold them back severely, which in fact it did, but not as badly as you would imagine. The Darts offer a small combustion chamber, 2.02/1.60-inch valves and a huge 225cc intake runner. That sounds like an odd combination when compared to the other heads, but the Darts are clearly designed with a head porter in mind. Sure, you can bolt them right on like we did, but their true beauty is in what can come from a trip through the port shop.

On the flow bench, low-lift flow numbers were quite a bit lower than the factory-ported pieces. In fact, the Dart head trails those tested here, clearly indicating that this is a LS1 head in an LS2 comparison. But, what happens with you open up that LS1 chamber, port the runners, and start blending the combustion chamber? You'll have to wait for another day for us to find the answer to those questions.

On the engine dyno, the Dart heads stayed right with the other competitors--that is, until they reached 5,500 rpm and the torque went away. Still, a little port work could easily solve that. The horsepower is right there, flat and broad from 4,500 rpm until past the engine's peak at 6,700 rpm. The Dart heads have a lot of potential, and this study only hints at what they offer the end user. All things considered, a Dart-headed LS2 would be hard to distinguish from the other castings.

Dart heads have always been known as affordable, feature-rich heads, and these LS1 versions continue that tradition. The Dart heads will likely really wake up big time with some attention from a capable head porter. If we do pull off a stroker test or better yet, a stroked/cam/nitrous test, the Dart heads could very well win the thing. As we said, the Dart heads are a bit of a mystery to us.

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