Bike fit / correct riding position

I have a question about crank length, (sorry if I have missed an earlier answer to this).

I currently have 175 mm cranks on my road bike and 165 mm on track bike. Given that the road bike is mainly for training, would I be better running a shorter crank to more closely replicate the track set up? Is there any injury risk or other considerations before switching to 170mm on the road bike? This is a live question, as I am changing groupset in July.

I doubt you'll notice the difference. I've got bikes with 165mm (track), 170mm (TT), 172.5mm (road) and 175mm (MTB) cranks and to be perfectly honest I can't tell the difference between them when I'm riding.