The rider needs to be WAY lower tucked. Rear swingarm needs to be a lot longer, and there should be an airfoil of sorts to direct air away form the rear tire, as that is a primary source of drag. And on a purely technical note, you would need a hugely overdriven final gear in your trans, a numerically low final drive ratio, or a very tall tire to hit 300 MPH with a 6500 RPM rev limit I shift my bike at 10600 RPM's and it's considered a fairly low revving bike, when you look at the 600CC'ers that spin to 15K.
1995 Mustang GT Twin-Turbo
Dart 377, Twin T66's, AFR's, F.A.S.T
2001 Suzuki Hayabusa
Velocity Racing Turbo Kit, Stock Swingarm Extended 4"