1994 suburban hinge gaskets-where to buy new ones?

[IADC43]

The barn doors on my suburban are letting the carpet get wet when it rains. I did the foam tube inside the weatherstripping trick. I'm sure the hinge pins are tight. I don't like the gap of the top of the doors, but other than tweaking them by bending them by hand, haven't seen where else to adjust them.
I put a hose on the roof and watched for water, I can see water come in and I am rather positive that it isn't coming from above the upper hinge.
The lower hinge gaskets look to be toast, I'm thinking that is where most of the water comes in.