Good point, and work with your steel supplier, before deciding how much you have to build up.
A long time ago, Ryerson flame- cut some u-joint yokes for me out of 7" plate. With a little Bondo, they looked pretty decent. Still in service as far as I know.
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA