Depends in part on how concentric the cam bore is to begin with...a lot of RB's especially have pretty horrific core shift and the cam tunnel is not trully parallel to the crank. I'll reject a lot of blocks for race use for that reason alone. After a line hone I usually try standard but I'll have a -.004 on deck, definately a game-time decision but I've found with good cam/crank squareness, more often than not I want a -.004.