ZZZZZZ,
My name is Randy Ritchey, I'm still pretty new on the forum so you probably don't know me, but I have built and dynoed bunches of 428's. It is very easy to get mid 400's HP and mid 500's torque out of a 428, especially with the Edel. aluminum heads and intake. Even with factory C8OE-N heads it is not hard to do. 450 HP and 550 ft-lb is easy to get from a mild mannered street 428 using the Edelbrock top end. If you are looking for all-out power, a well built and balanced cobra jet bottom end with Edelbrock top end and a healthy solid or roller cam can push 600 HP, but I'm talking about a rough, barely (if at all) streetable motor. But in reality, how much power can you harness on the street? 450 horses will melt the best street tires on any cobra, at a 30 MPH punch. If you are looking for a good, dependable motor I strongly recommend the Edelbrock heads and RPM intake. Their cam is good too, but you can do much better with a split duration cam to help those exhaust ports. You will end up with more power than you will ever need and still have good street manners. I hope this helps, and if you have questions feel free to ask. You can e-mail me at
randy.ritchey@atkinsamericas.com if you want, I don't get on the forum that often. If you are looking for help getting a motor together I can fix you up with a beauty. Thanks!