LSA/LDA vs power production ??

5500 is way to high for a street engine IMO and I think it's closer to 3000 RPM's give or take 500 on ethier side for a street driven machine. That's more real world to me. I know theres guy's out there driving cars on the street that make crazy power and peaks @ 5500 or better, but that isn't really a street driven car by the average driver of a hot rod.

The exhaust and head issue is another part of the article that just assumes a "Stage" of build they think is more likely to be on the street over a stock headed engine.
In chassis engines and performance parts are allways limited to the cars sheetmetal and of course, there performance potential.