what kind of rear gear are you running and if its an auto what stall speed is your torque converter? you've got it down right with the vacuum you should be getting it to as high as possible at idle with the proper idle rpm, around 650-700.... thats not really a big cam so i doubt its cam specs that are throwing you off.... she should start making power at about 1000 rpms..... i would look more into the carb, rearend and torque converter now to really bring it to life.... if you've got a 2.73 gear or something you'll never have any torque out of your motor.... i'd run at least 3.73 but i'm lookin closer to a 4.10.... with maybe just a mild torque converter maybe a 1,200 rpm stall speed