Mine came from Oshawa, Ontario Canada 70,000 miles and only used to haul a camper. Never winter driven, which means more up here then it would down there
Unfortunately the other difference I have is the leaf spring rear.
My speedo has been running too fast ever since I got it and I have 4:10 gears also, I will have to try the speedo gear combo you have in yours to see if that will make it right