I got that same speedo/tach combination for Christmas this year. I put on in about 15 minutes. I think it's more accurate than the stock speedo that came with my '12 FLSTC. Looks great, works great. No tank removal either. One very small thing - it synchs with the ecu after 31 miles. After that, you can't use it on any other bike.
Hi u will also have to plug it in to the data link under the seat to download the k's opps miles to ur new speedo I had to cheers.