Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Noisy Mazda thrust bearing?

The background why I am so interested in the 4/4 gearbox and its control is the following. At the older Salisbury rear axles of the 4/4, it was relatively easy to change the final ratio to 4.1. A different gear rim was simply exchanged. The disadvantage is that the motorway engine speed also increases significantly. On my 2014 4/4 with BTR rear axle, this simple change no longer works. I would have to buy a completely new axle. Techniques and Williams confirmed this fact four years ago. At around 6500€, this is far too expensive. A 6 speed NC gearbox would have pretty much the same effect as a 4.1 rear axle plus almost the same low cruising speed in 6th gear. In the pictures below, a, the comparison of 5 speed and 6 speed NC transmission, b and c 5 speed with 4/4 wheel circumference, d and e 6 speed. I would very much like to be able to fit a 6 speed gearbox. Despite an intensive search, I have not yet found out whether an NC 6-speed gearbox has different dimensions, especially in length, or not. In the worst case, I would have the propshaft shortened.