Maybe, but if you took a camplate to a machine shop and said you wanted one mirror image plate, the cost might not be so different.
I revised the ratios after some discussion with Allen, making the overall range wider. As John stated, races are only six or so laps long so whoever gets to the first turn first is likely the winner. Maybe different down under.
Here is a comparison of various gearbox ratios:
Quaife is perhaps the worst, with the bad dip in the 4th gear. The third shift (3-4) drops 754 RPM and the fourth shift (4-5) 1427 RPM
The Triumph five speed also has a slight dip in 4th. Third shift drops 1125 RPM and the fourth 1197 RPM. Triumph's 1st is 2.585, slightly lower than the stock A65 1st 2.513. Probably because the Triumph does not have as much low end torque.
Hill's has a good shape and is a close ratio box, starting with a lower numerical ratio than the stock four speed, 2.294 versus 2.513.
I made the ratios with first the largest that would fit in the box, 1st is 2.786. I thought about making the fourth gear 1:1 and fifth overdrive, but it made the RPM drop between 4th and 5th small and the 1st gear RPM drop large because 1st, 2nd and 3rd has to go through the 5th gear ratio to get to the high gear.