wrench87 You are running 7,300 rpm with a stock performer RPM, on what motor? This manifold out of the box was tested, and the power band for it is lower at max then what edelbrocks shows. I would like to see the dyno runs with this setup and some of the specs on the motor. It is possible to turn a motor to 7,500 rpms with this manifold, YES been there done and seen it. power drop off was huge. This is way single planes where made for this kind of rpm range. I have Dyno 2000 and another software motor building CD. Both come within 3-4% of real numbers. Last 3 motors built where done this way and on the motor dyno and chassis they all ended up about 5ft of torque and 7-8 hp off. Sound like a nice magic motor you have.
Back to you motor, I think you will find that the camshaft you have is got a max of 6,400 rpm for the HP band. I also have one of KCR special cams that is a little bigger and it tops out at 6,700 rpms, .622" lift. Hydro lifters are heavy. They pumpup at high rpms. Strong springs will help control bot if you have them adjusted like both directions say the valves will not be closing and the motor falls on it's nose. Again been there and have dyno sheets showing this problem at 5,800 rpms with a 587-607" crane hydro roller. I am also running beehive springs. With turning 6,200 rpms and the lifters being pumped up, my motor runs like a solid lifter one but without the major power lose. .015" plunger depth when adjusting the rockers. Even with stromger springs about 6,500 rpms your motor will hit the wall too. Solids are the way to go for higher rpms with more power. I don't build HP motors, only torque ones.
You have nothing to loose with starting with the 650 DP. Thrown the motor on a dyno and see what the numbers are. Play with the camshaft timing. If the numbers on the dyno are not what you want, go to a bigger carb. Remember that dyno testing and street testing are not the same, and bigger is not always better. You are also not running a huge cam in this motor. You are running a 445 motor switch is 20 cubes more than a stock FE. My 482 eats up the 587-607" without any problem. Little lope and 14hg if vacuum at idle of 750 rpm. steady. You might want to search on the FE forum for some more info.
Rick L.