What needs to be done to the trailing B-A unit in an A-B-B-A set?

[BeeleeO9]

I have two Bachmann F7A-B units, regular DC (no decoders, etc.) I want to make up an ABBA set.
Can I change some wiring in the trailing B-A unit to make it run in "reverse?" That is, to pull in the same forward direction as the leading A-B unit. This is for a primarily static display of the GN Empire Builder. I may take it and some of the consist (upwards of 18-20 cars) to visit friends' layouts. Thanks for advice.

Another question...on the F7 A units, just in front of the windshield, there are some black strips, parallel to the track. Are these anti-slip textured areas (like on boat decks) or something else? It seems they might be safety step-zones for crew cleaning the windshield or similar task.

Regards, Bill

[jward]

you don't need to do anything. with dc, the direction is determined by the polarity applied to the rails. any locomotive sitting in that block will move in the same direction regardless of which direction it is facing.