For me 700 -750 CFM .

As for your camshaft yes you could step it up . But as for 235-240 at .050" on a 10.5.1 350 ? Re-check that math .

This 355 has 10.5.1 and runs a 230 dur at .050" .

http://www.youtube.com/watch?v=qkK0Wu9QEys