There is no real difference between series II kingpins and 1000 kingpins, so if they are not worn, trunions or kingpin threads, there is no need to change them.
Brakes depend on the engine size and if you are increasing power, if still using the original 803cc engine then the original 7" brakes if well maintained should be fine, adding a servo would reduce pedal pressure.
Options to upgrade would be changing the front drums/backplates and internals to 8" as per 1098 minor, the hub remains the same as does the kingpin, again servo option applies if wanted.
If you are increasing engine power then front discs are a good idea, there is less brake fade on repeated use, an early Marina disc conversion if you can get it comes with an adaptor to enable the Marina hub to fit the Minor stub axle, the hub may or may not come with the kit. standard Minor wheels fit the early Marina stud pattern which is the same.
There are also other disc conversion kits available that can provide the standard minor stud pattern.
A servo with the discs reduces pedal pressure but is not essential.
Rear brakes were only ever 7" on all series II and 1000 models.
Your rear axle should be the same as a 1000 axle so no need to change that, if if increasing engine size you may want to change the diff to a better ratio.
Minator wheels are available to fit the standard Minor/early Marina stud pattern.
For reference I run a 54 Series II convertible, it has it's original rear axle and 7" drums with uprated halfshafts and a higher ratio diff.
At the front it uses Marina discs. I don't use a servo. Engine is a fast road 1275, brakes have proved fine. I always use silicone brake fluid which prevents deterioration of brake cylinders.
richardsthom wrote: ↑Fri Jul 03, 2020 12:28 pm
Your rear axle should be the same as a 1000 axle so no need to change that, if if increasing engine size you may want to change the diff to a better ratio.
I believe that on the earliest SII cars, the axle and brakes were as fitted to the earlier Series MM, which could be why he is asking about potential need to change the rear axle?
Whilst the early Marina to Minor disc brake conversion (Mr Grumpys) did indeed have an adapter that fitted over the stub axle to allow fitment of the Marina hub to the Minor stub axle with different wheel bearings, that has now been superseded by a completely new hub which does not require any adapters. The original adapter was/is available from ESM but being ex Bull Motif stock is not listed on the ESM web site. You have to ring up and ask for it. I recently purchased qty four adapters from ESM and stock was low then.
The wheel PCD for a Morris Minor is 4", the PCD for a Morris Marina is 3.75" therefore the wheels are not interchangeable.
Mr Grumpys original disc brake kit was supplied with modified Marina hubs that gave a PCD of 4". I have these fitted to my Minor.