You've just entered the horsepower race and you have tied a cast iron head to your leg. Not logical to me. You should know going in that either the 915 or 906 (or any of the other open chamber heads) will flow, stock, a maximum of 230cfm. That'll just barely get you 500hp and is the reason the poster above had to crutch head flow with a pretty big cam.

Furthermore, unless you can find a set of heads that have already been ported and have a fresh valve job, you will spend more $$$ getting them ported and ready than you would on a pair of Stealths. Fast68 did a writeup on the subject and he's a professional head porter.

So before you spend a nickel on your cast iron heads, get a written quote on the cost. Then compare alternatives.

Another fact to consider is that Chrysler dyno tests of stock 440s usually ended up with a maximum of 335hp, and that's after hours and hours of running. This was covered in Mopar Action (RIP) several years ago in an interview with a former Chrysler employee.

I understand nostalgia, it can be powerful at times. Yet, the advantages of more modern technology are very hard to overcome with the old style parts.

R.