well guys, now this really worries me. when I did the dyno figures, I was using the old head values, with the old valve sizes from the old head, thought they were the same but, the old is 1's are 1.55/ 1.388 and the new head valves are 1.754/ 1.392. so now it says 397 HP @ 6,000, respectable 341 @ 5k, and a flat torque curve, right around 300 ft/ lb. I know my original 7 1/4" rear end will not handle it for long, maby it will hold out for a while, as the power comes in around 2k, but I'm not too shure. A Maverick or Granada 8" might be in order pretty soon.