You don't have to use T&D's, you can run anything from the factory non adjustables to stud mounted 351C type rockers. Check the pictures here.
http://www.garrettmachine.com/cylinder_head/bluethunder_fe_alum.htm
These billet heads sound interesting. Canted valves sound like a pretty radical departure from the FE norm. I'm not sure there's a very big market for that but i'd love to see them.
It took till very recently for anybody to come out with a raised intake port smallblock Ford head and that's a huge market. Many racers did quite well with low port inline valves on those motors.
