a 351 W will look like this
http://i41.photobucket.com/albums/e2...sport/351w.jpg
and a 351 C will look like this
http://i41.photobucket.com/albums/e2...sport/351m.jpg
now for the fun part. the picture is of a 351M. the M and C engines look alike, but the M engine uses a bell housing bolt pattern shared with the 351M, 400, 429, and 460.
the C engine, has a bell housing pattern of the 6 bolt 289-302-351W engines.