Ok, so a frustrating day at the dyno. The 289's distributor decided to roll smoke out from under the distributor cap because a Pertronix module died right off the bat. Then the distributor cap had the terminals so far down that two of the plug wires wouldn't reach and I had two dead cylinders. Fun stuff. That's why we dyno.
The 428 went perfectly and basically fell in line with the horsepower that my factory-ish 428's usually make. This one made quite a bit more torque though.
The 289 made 309 hp @ 5750 with 316 lb-ft of torque.
That build should have been built with Dart Iron Eagle heads, which usually flow around the 270-280 mark. However, Dart is redesigning their IE heads and kept pushing back the release date. My customer finally told me to pop some World heads on and let's go. Obviously they are a little better than factory, but they are not Dart heads....
The 428 made 435 hp @ 5250 and 482 lb-ft of torque. I think we had a couple of 490 lb-ft pulls, but we ended up tuning and catching a little more horsepower.
Who are the winners?
