You're reading his signature wrong. He's not saying KAs are better, just that SR isn't better than a KA. Yes it's semantics, but they're important.
He's just trying to dispell the myth that the SR is automatically better than the KA, which it isn't. Both are capable motors when built.
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Got a 1995-1996 240SX? Want a new front bumper?
Check this out. Posting on drag first to try and avoid shipping it.