Use a good body seam sealer from a body shop supply , thats all you will need. Tell them what you are doing and they will get you the right stuff.
Sounds OK, looks like there was a gasket material there when I took them out. I'll talk to the supply house.
Thanks
7D2N
caulking doesn't paint very well.
Latex or Silcone do not paint well. But Butytl Rubber and Polyurethane gutter/roof sealer do. Plus they don't dry out and crack.