Ferrigno did / does pretty well.
Labrada
Don Youngblood - his trucking business was pretty big.
Pudzianowski - Trucking, plus other ventures.
Vic Tanny - Old time bodybuilder, had a big gym chain.
Walter Marcyan - Universal and Marcy Gym Equipment.
Bill Pearl - He did really well off publishing I believe.
John Terpak - Went on to be an executive at York Barbell.
Dan Laurie - Gym line, publishing, etc....
Jack LaLanne - He did a few contests, so he counts.
Anatoly Pisarenko - Big time Russian Weightlifter, got into the Russian oil business hugely after the fall of communism there.