You really don’t. There may be some very specific engine combination (4 valve, static rpm, weirdo stuff) where a cam might be spec’d with reverse split durations like that and be optimal, but all the testing I’ve seen just doesn’t show them making more power. In fact they give up a bunch. On a typical street strip small block wedge head the split pattern almost always makes more power. I went with the advise of a well known cam grinder on a big block remote turbo deal I built and he ground me a 224/218 @050 .510/.510 reverse split and i wasn’t happy with it. Had another cam ground 226/231 @050 same lift and made 100 more hp on less boost. So my opinion is slightly viewed one way.
