Sounds like a terrific upgrade. I've been excited about it since you posted a week ago. Driving and imagining how it would change things.
However one of my concerns is wear and longevity. You mention the engine spins 800 rpm faster at 75mph, that is a pretty large jump up. Does anyone have a feel for how much increased wear would result with this. Would it be bad at very high speeds? Sometimes I like to race airplanes
Further I have a feeling that the trans would be put through more torture? Very exciting mod however.