Just checked and read through the 350 route so the main parts are

Both follow each other from Newcastle to Holystone Park Francis Way. Then the 351 will do as it does now but 350 will come out of Francis Way and turn right and go to the A19 that way (like the 351 on the evening does)

Then they follow each other into West allotment. 351 will follow its route as now. 350 will turn left and follow the 353 to the bottom of Shiremoor where it will meet the 351 again.

Both follow each other again but the 351 will turn into Earsdon where as the 350 will pass it straight ahead and rejoin at the roundabout

Then from here they split until Whitley

351 will follow the route it does now

350 will follow the route of the 57/57A (not serving Sainsbury's) and just going straight ahead to West Monkseaton metro and then going straight to Whitley Bay via Monkseaton Metro (57/57A route)