[blykins]

I dyno'd a 428CJ yesterday with factory heads and intake. Only real upgrade as far as performance was a hydraulic roller cam, along with a better valve job with Ferrea valves. The heads flowed about 250 on the intake side, which is right around where the Edelbrocks flow out of the box without any port work.

This engine made 422 hp @ 5500 with 466 lb-ft of torque at 4000 rpm.

I have rebuilt engines from Southern Automotive where they have used Edelbrock heads, and they did not do any port work to the ones that I have seen.

With that being said, I would imagine you're somewhere in the 425-450 hp range, even with the Edelbrock heads.