The most successful one I can think of is Bert Emanuel who played QB at Rice and then wr in the NFL.
I grew up watching Southwest Conference football and loved how that guy played in college and it was cool watching him be successful in the Pro's.
The only other one I can think of that produced a little most recently was Arnaz Battle.
What i saw from Bert him was a full commitment to the position change. I seen a lot of failed attempts like Eric Crouch and several other but I think those guys where never committed to the position change after being the Big Star and wanted o play QB still.
"It is the duty of the patriot to protect his country from his government."