I agree. I know a guy running a mildly worked set of X heads on a 408 in a 69 Dart and with just 3.23 gears and a 3k stall runs high 11's. Put it together and have fun while your saving up for some really good heads. Doing a top end swap isn't that much work
My guess is you can run the Voodoo cam even though the exhaust lift is rated at .566 and you say the X heads will only support .550 lift. Reason being is the lift loss due to the complex pushrod to lifter angle is anywhere from .025-.040". That puts the Voodoo cam at a max valve lift of no more than .540".
