Dual filament bulbs are for dual filament sockets. They MAY work in a single filament socket, depending on the size and configuration of the socket, but they are just as likely to not work. If you do transition to LEDS, it can be done without resistors, as noted by dizzle but some years may have an additional issue of backfeed thru the signal indicator light in the console that causes all 4 signals to flash whenever a signal is activated. That issue is also easily resolvable with 2 diodes and a pigtail in the wiring inside the headlight assembly.