John, Consider getting a hydraulic lift table at Harbor Freight or Northern Tools to lift heavy wood off of a truck and onto your lathe.A lift table can be very handy getting around the shop.
As far as turning large bowls, boiling for a couple of hours can help as several have suggested, but I also suggest turning more than twice on large bowls. This way there is a smaller amount of warping to deal with each time being turned and ,thus, less bouncing tools & shaking on the lathe.
As far as turning large bowls, boiling for a couple of hours can help as several have suggested, but I also suggest turning more than twice on large bowls. This way there is a smaller amount of warping to deal with each time being turned and ,thus, less bouncing tools & shaking on the lathe.