There's a ton of junk on the market in "LED bulbs". Good ones to fit the bayonet-type sockets in your '64 are available but unrealistically expenisve. Instead, buy '66-up sockets to accept the wedge-base bulbs. That's
these (sold individually, one "each" at the listed price, even tho the pic shows two—hence why two buyers left upset reviews, thinking one money got them two sockets) and install the good bulbs. That's
this yellow one, top pick for general dashboard illumination, much brighter light without glare that you'd get with the white bulbs. Red (high beam, oil pressure) is
this one. White is
this one. If your cluster has a single turn signal pilot light (same light flashes green on the dash whether you're signalling left or right) then you can't use an LED in it, because those single pilots work by current flowing one direction for a left turn and the other for a right, which is fine with a filament bulb but LEDs only pass current in one direction).
