led tail lights

[1969stepside]

this might have been posted before but here is my question well two questions really first i am converting my 69's tail lights to led and i am using the 55-57 stainless steel step side tail lights what all will i have to do to make this conversion possible and will i need any extra parts or new flasher with a ground coming off it? i can post pics if needed of the lights. second i converted my gauges to the white faced ones that come form whitegauges.com and i am a little worried about the numbers not showing up what can i do there any info on either of these problem will be helpful