I have a York T874R1046 Thermostat. It is wired:
white wire to w
blue wire to b
green wire to g
red wire to r
black wire to x
orange wire to o
yellow wire to y
I am replacing with a Trane TCONT401 tstat.
My question is how to wire up the base of the new tstat.
It has a terminal strip with - R, W2-X2 on same terminal,Y,G,O,B.
Everything seems to be straight forward except what I do with the black wire? Since it is on x of old tstat does it go on the x2 of new one?

look at the install sheet, I`m thinking the black=x wire should be used on the c=common post