By the same token the 170’s will need to be easily identified as 170’s.
It's a lot easier to tell the difference between a 156 and a 170 than it is to remember that any of the 9 ex-GA units (02, 07, 09, 12, 16-19, 22) can't couple to the ex-EMT units (01, 03-06, 08, 10-11, 13015, 70, 73, 97-98)...