I don't claim to be an expert at 6V to 12V conversions. I did one conversion on my old 55 1st panel though. For the conversion I changed the coil, voltage regulator, generator and bulbs period. I didn't add a resistor or anything else to drop the voltage to the guages. All of the guages ran with 12 volts with absolutely no problems and I put over 100K on the truck after the conversion. I don't think you'll have any problem with your guages but I still wouldn't turn your lights or any accessories on while the 12V battery is hooked up to it. A lot of folks here strongly advise dropping the voltage to your gauges & while it certainly can't hurt I've personally not seen a probem with not doing it.

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