The 19T will fall off before 6, I can't see that small of a hotside holding past that.
The 35 will go till MAYBE 6300-6500. It comes from the AUS STi's and EDM wrx's that were bugeyes I believe. Not 100% positive, but I'm pretty sure that is what I read online somewhere.
The powerband for the 35 is incredible. It won't produce high numbers, but it's been many peoples' favorite dd auto-x turbo out there