On the Gallery page, I have put a table of the most commonly available gearboxes with the standard 5th gear ratio and also with the Ron Welsh 1:1 straight cut 5th gear which can be fitted without dismantling the main gearbox.
One table gives the individual ratios and the other gives the overall ratios.
For comparison I have also shown the overall ratios for a race Reliant gearbox with a 3.9 and a 4.2 final drive.
The 900cc Seicento gearbox is different from the others and needs an adaptor plate to fit the FIRE engine. This is not suitable for the Falcon. Of the other gearboxes the Grande Punto and Punto 55 Cabriolet can make use of the standard 5th gear , but in my opinion would be better with the Ron Welsh 1:1 5th gear. The others really need the 1:1 gear for 5th to be of any use at all
The Grande Punto has a higher torque capacity than the earlier versions and is the one I have used in my Falcon since it was first built.