I got an 84 reg cab; they're flat 'cause I couldn't make 'em angled. (no body lift) They work fine; it's all personal preference. Before I finally welded them on I tacked one side angled (couldn't open the door) and one side flat... flat side won out. Plus think of when you land on something... they may bend upwards.
Do what suits you and what you run over.
>>Dan