You can use an open train times site such as
http://www.opentraintimes.com/ to find out what route the train takes and details of any additional time for pathing, engineering allowances etc, as well as the WTT (working timetable) times.
This train is actually the 0415 from Newcastle:
http://www.opentraintimes.com/schedule/G02379/2012/8/30
(In the top-right you need to choose detailed mode to get the extra detail)
As you can see, there's a lot of allowances there, and WTT arrival is 3 min earlier, so it would seem
likely to arrive early, though not by much as the 0749 GC is timetabled to use the same platform.