I picked up a plm roller from the East Coast and am trying to figure out how much backset I need for new wide 5 wheels. It measures 63" from hub face to hub face. Anyone know what I need to be legal at Dixie?

A 10 inch wide racing tire. a 5 inch offset all the way around will put you straight up in the middle (whatever your hub to hub measurement is). What tire are you running? Dixie runs the 970 tire on a 8 inch rim. So will have to figure out what your left side % needs to be. Your wheel offsets will determine this.

Yes, it's the 970 tire on an 8" rim.

Most likely 2" right side 4" left side some are running 2" & 3" but that is cutting it close. This is for 8" wheels.

Do you think running 2" and 4" makes much difference than running 3" on both sides?

More left side weight.