The only problem you may encounter is a u code being thrown. Some of the speedo/tachs has a clinch with the older models. I had a hd combo and it threw the engine light every few minutes. Serial data is the code it showed. I finally went with a Dakota digital. It even shows what gear your in. There is no fuel gauge but it has a mileage count down. You can find it easy enough for around the same price.
just a thought.

 

I'm on a phone so forgive me if this has been answered in detail
The main difference is the CAN BUS, this is what the vehicle information travels on, like tach, gear position, distance to empty calculations, in 2007 Nope, 08 some models, 09 most models
I installed PN 70900001A on my wife's 08 FXDF Fatbob, the tach,speedo, clock,odometers, switching from Kms to Miles all work great, 6th gear and neutral lights work fine. The only thing that doesn't work is the trip/distance to empty calc.
I am fine with that, as we wanted a tach and also to switch from Km to miles, when you order it from your dealer you have to give them the mileage and Pre pay, and it come "burned" with the correct kms or Us miles, after that it is plug and play
Cheers Ultra

 

I just installed a new combo speedometer on my 2011 Road king classic! I got a great deal less than 1/2 price at a open house sale.
I installed it the next day took all of 45 minutes and I am no Harley mechanic just a do it your self-er. No problems I followed the instructions for a change. Also there are you tube videos that I watched first.
New speedometer works great as advertized and looks good .
Sam