Dart Cylinder Heads - 500HP For Cheap

Bonus Power: 383 TestIn the course of our thrash we got derailed a bit and tried the Dart 215cc small-chamber heads on a cast-crank 383 we had in stock. This engine used a Comp 306S solid flat-tappet cam with 260/260 at 0.050 and had forged Keith Black flat-top pistons set at zero deck. They, too, needed lots of handwork to get sufficient valve-to-piston clearance. Compression wound up right at 12.0:1, and the power with the Victor Jr. intake, 2-inch spacer, and 850 Speed Demon was 530 hp at 6,600 pm and 497 lb-ft at 4,900. We also ran it with an Edelbrock Street tunnel-ram and a pair of 650-cfm TR Demons and made significantly more power: 568 hp at 6,600 and 512 lb-ft at 4,600 with gains everywhere in the rpm range.

While the 383 made more power than the 350 (duh), its hp/ci was not quite as good and its rpm rolled off sooner. We'd conclude that the 215cc Iron Eagle is a little happier on the smaller engine when turning in the 6,000-plus rpm range, so we'd select the 230cc intake runners if we were going to do it again.