I don't remember the port letter, I think A, but it's the top port on the set of remotes that has the detent (left set in my case). I have not tried using the other port. But the dealer didn't install the dump kit when they installed the hoe he said that there was no advantage to it. He gave me the kit and I installed it and have used it both ways if I know that someone other than me is going to use the tractor I don't use the dump because I don't have to worry about it getting deadheaded if they bump the levery the wrong way. I don't think I can tell the difference in either configuration, but next time I run it I will swap to B port and see if that makes a difference.