Your response seems to be the most seemingly accommodating, again, I'm not skilled in modifying Mopar engines for higher HP (most of my experience is Chevy). This is why I'm asking. I chose the 587 heads because a pair were readily available to me, and it seemed to me that installing them would help the engine breathe better, along with a 268 cam, 4 barrel intake with 650 CFM carb, and headers, with a 2000 stall converter. Because I have to work on the rear end anyway, it was my plan to install an 8 3/4" Sure-Grip for better traction (should I require it). This was my plan. I want the car to be "streetable", not for racing. Thanks for your info.