higher I vaguely recall a 0-7 away win at Southport or somewhere millenia ago
Possibly you're thinking of the 8-0 win over them at EP in March 1970.
We've one away League win by 5 goals, a 6-1 win at Swansea 23/09/1989.
A couple of 6's. Last one was 6-0 at Plymouth 12/03/1949.