400 braking improvements

[Superfine]

The 400 standard original braking performance is really inadequate for modern day traffic conditions and I intend to fit to my 400 a 405 front suspension unit complete with late type 405 disc brake wheel hubs using Coopercraft 4 pot calipers. I will also fit a brake servo, brake bias valve for the rear drum brakes, steel braided flex hoses and 405 anti roll bar.

With the improved braking I feel I also need to fit the wider 405 wheels in place of the narrower.400 wheels to increase the tyre contact footprint..

Has anyone got any hands on experience of a similar upgrade on a 400 please?

I am particularly concerned that using the wider 405 wheels,. there may be. interference with bodywork and suspension. I do realise that the spare wheel cover won't accommodate the 405 wheel and tyre..

Any advice would be appreciated. Many thanks