If your carburetor has a big vacuum port at the base (presumably it's capped right now), then it's already calibrated to account for airflow from the PCV valve. If not, then not. Often this can be compensated using the idle mixture adjustment needle, if the carburetor's in basically good condition.
An under-carb spacer with a PCV fitting was not used as factory equipment, but was part of a kit Chrysler offered briefly in the '60s during California's experiments with retrofitting emission controls to cars not originally built with them. It makes the hookup easy, but creates other problems: the automatic choke will no longer work correctly (rod too short), your kickdown linkage, if your car has automatic transmission, will effectively be dramatically shortened (and may not have enough adjustment range to make up for it), and your throttle linkage rod will be lifted up at the carburetor end, which can cause bushing wear and binding. Better to avoid lifting the carburetor higher than it's meant to be, and drill/tap the outboard wall of the intake manifold's plenum for a brass fitting with pipe threads on one end and a hose barb on the other. Do not try to connect the PCV hose to the fitting on the rearmost manifold runner; you'll make № 6 cylinder run lean and burn-burn-burn.
Another option is to install a carburetor equipped with a PCV port.
Once you've got that figured out, remove the road draft tube, install a PCV cap and valve, run a length of appropriately oilproof hose from the PCV valve to the carburetor port, readjust your idle mixture and speed, and you're all set. The PCV cap you'd need to keep using your pre-'66 valve cover looks like a roughly 2" diameter metal version of an aerosol spray can cap, with a hole in the middle, and it uses a 2-legged steel spring to hold it firmly to the valve cover chimney. Kind of a fiddly nuisance, but it can be dealt with; the cleaner option that still retains a highly original appearance is a '66-'69 valve cover (same as earlier covers but has a rubber grommet instead of the rear chimney).
Picking a PCV valve requires some caution; many different valves will fit and look alike, but they have different flow characteristics and spring calibrations. The 170 engine takes a different valve than all the larger engines including the 225.
The original '61-'63 valves were a metal item made by AC and designed to be taken apart for cleaning. I might still have one or two of those new in box (and the separate metal elbow they take); ping me if you want me to check.
If you don't want to mess with hunting up obsolete parts and you'd prefer to shop for a current-production PCV valve, the one you want is Chrysler/Mopar № 05175351AA (or just 5175351AA if you prefer to omit the leading 0), such as this one (or you can pay triple the price if you want). These currently-available PCV valves are a different style, made partly or completely out of plastic, and require some adaptation to use with the pre-'66 valve cover and PCV cap. You make a sandwich in this order: PCV valve (push the non-hose end through the cap from outside to inside), spring retainer, grommet (push onto non-hose end of PCV valve from the bottom). Sometimes the spring retainer won't fit over the plastic valve and you have to leave it off. Push this "sandwich" onto the valve cover chimney. It won't look quite original, but it'll fit and work fine:
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