Does anybody know if I can use forwards from a 2016 48 on my 2013 iron? 

No you can't without changing the brake rod. The lengths are different as is the fitment at the master cylinder, the pre-ABS ones are longer with a rose joint on the end, the ABS models have a shorter rod with just a hole in the end as it fits into a socket on the master cylinder.

I have a 2012 48 with forewards if you would like to swap.