Getting power out of a 63 /6?

Well, first make sure it's in top-notch tune. Tune-up parts and technique suggestions in this thread. If the motor's got some miles on it, check for timing chain slop, too; see here for instructions.

Once it's time to move on to upgrades, a good electronic ignition swap is an excellent starting point; I like the HEI upgrade . A 2bbl carburetor swap should be on the docket. It's not as easy to do on a '63 as it is on a later car with cable- rather than rod-operated throttle, but it's certainly not impossible. You can either swap in a later cable-type accelerator pedal or do some fabrication and adapt your 1bbl intake manifold and rod-type throttle linkage; see here. When it's time to replace the exhaust system, put in a 2¼" headpipe and a larger-than-stock, stock-type muffler for much better flow without annoying noise.

The next round of upgrades is more involved and costly. See for example Dutra Duals and header options discussed in this thread and this one, Erson custom cams, HEI ignition upgrade, Mike Jeffreys windage trays, Hurricane intakes, other exotic intakes. Hi-perf engine buildup here, high-perf parts and build info here.