Red90

Yah, you just need good shocks on a Defender. You won't find much that can keep up to you on a rough road.

One or two teeth and it will run as described with no mechanical damage. The valve and injection timing become retarded and they smoke heavily. The other possibility is if the pump timing bolts come loose. It becomes heavily retarded and the fuel is injected too late producing lots of smoke. My question on the engine oil is to do with a failed turbo turbine side seal. This causes lots of smoke.

Are you losing engine oil level?

The type of springs is not an issue. Air springs can be fine. The problem is the short arm independent suspension. It is horrible for keeping wheels on the ground. IT only takes 5 minutes off road with anything LR has built in the last 10 years (other than the Defender) to see this.

Yes, you still want vacuum advance.

As already mentioned a few times. The screws are self tapping. The holes are not threaded. The screws tap into the stalk. You use the screws that came out of the old one. I did this a few weeks ago.

The flywheel is one of the friction surfaces for the clutch. Much like brake discs, having it machined to be flat provide the best friction and ensures the clutch does not wear prematurely. Unless you enjoy changing clutches, it is a good idea to do things properly while you are there. It is not an expensive thing to do.

Britpart sells GKN branded shafts. The part number will have a "G" on the end and when you get the shaft it will have a GKN label on it.

That link is for the old style without intermittent function. 1990 and earlier.

What happened to the existing screws? Normally you just reuse. They are no bolts. They are self tapping screws that thread into the metal. I just did one of these a week ago. The new OEM switch did not have screws. The screws from the old switch just moved over. The three screw version is the early, non intermittent style.

They are just self tapping screws. The later ones like the one you posted only uses two screws.

Yep. That is the problem. When you are on a steep hill and need power, the TC takes it all. Even on this flat ground, you can hear the engine working hard. As above the rear locker helps a lot if you have one with that option.

https://merlinarchive.uk/vehicle/LU46AA

You need to be running below 10 psi and need lockers to give a trail a difficult rating. If you can drive through on 60 series tyres at road pressures, it is an easy trail.

No, those were all easy trails. You barely need four wheel drive to tackle them. If you do not understand where low pressure is required, then you have no experience on hard off road terrain.