I googled "drive from Blackpool to Great Yarmouth." There are several routes, taking 5 hours and 19 to 30 minutes. A recommended route will come up on a map on various websites.
Shortest seems to be M55 - M61 - M62 - A1(M)- A1 - A46 - A17 but other routes are available, as marg6 suggests. Getting around Manchester is the trickiest bit. I never seem to go the same way twice.
If I go to Norfolk, from north of Manchester, I go M62, A1, A46 etc. And if I go to Blackpool I go M62 M60 M61 M55. So add the 2 bits together and you get Fiona's route.
When you get down the M61, following Leeds M62 will get you to the M62 going east.