[DZ Fool]

Im looking to improve the shifting of my Doug Nash .

Any thoughts

[JodysTransmissions]

The shaft centerline is 82mm on these units or almost 3.25" which makes them a heavy shifting gearbox.

To really make Doug Nash/4+1 or ROD 6 speed shift better, you would need to lighten all the gears as much as possible. Liberty Gear can do this job but, that is expensive.

Blueprinting........

There are better synchros and sliders with small strut keys for better shifting. Also using lighter springs in the synchro assemblies helps. Dial indicating a bellhousing to better release the transmission from the engine and slow down the gearset during high RPM shifting. The interlocks need to have enough clearance when the transmission is up to temperature.