Light bulb chart

See here. Get the good ones and don't faff around with off-brand Chinese trinkets.

The only "gotchya" points are minor: LED means Light Emitting Diode. A diode passes current in only one direction, not both like a filament. So if your car has a single green pilot light that flashes no matter whether you're signalling for a right or left turn, don't put an LED in it. And for the rest of the dash lights, it matters which way round the bulb is installed in the socket (or the socket in the circuit board). If the LED is installed backwards, it won't light when it should. If there are other LEDs in the system (as there are in the dashboard) then just one backwards LED can create weird new paths for electric current that shouldn't be there, causing a no-light or no-light-when-supposed-to or light-when-not-supposed-to situation.

So, fashion a jumper to ground the cluster properly (when installed in the dashboard it grounds via dashboard metal). Install one LED bulb/socket assembly. Try it out to see if it works correctly. If it doesn't, remove it, turn the bulb or the socket (not both!) 180°, and reinstall it so it works. Then move on to the next one: install one more LED bulb/socket assembly and try it out. Proceed this way until all the bulbs are installed and working.

Note the links provided here are for wedge-base bulbs as used in '66-up cars. Legitimate bayonet-base LED bulbs are much scarcer and more costly; easy workaround is to install the '66-up dash bulb sockets for the wedge-base bulbs. They fit right in place of the earlier sockets.
Thanks Dan. As always, great information.