1986 110 engine swap

hi, I have the option of 2 engines for my transplant.
1. Complete discovery 300tdi 1994
2. Complete 90 300tdi 1997.

It was a 2.5n.a. That came out.
Would the 90 be the better option for fit or the discovery?

Sorry. This is a 1986 110 ex military motor. Was fitted with a 2.5 nav diesel.

There's nothing in it, the engines are more or less identical, with the exception of a bracket under the cylinder head nuts on the Defender application.
The gearboxes are the same too, but the Defender has a different gear change setup, which you'll want to use.
Use the complete 90 assembly, but only if the engine is as good as the Disco' one..
You will have to re position the engine mounts on your 110's chassis.

Is the Disco manual or automatic as the fuel pump and injectors differ. If you're keeping your lt77 then there's no difference in they are both the same so go for the lowest mileage

The engine in the defender is sweet as I've heard it run.
The discovery engine is untested but been promised it's good. I've had other bits off this bloke and he is yet to lie to me.

So, the engine mounts will need moving regsurdless of what engine I choose. Think I go for the defender

The Defender one is your best bet then. Get everything you can under the bonnet, particularly the air cleaner, all the air hoses, radiator and particularly its frame, etc.

If you fit a 300tdi from the defender will it mate to the lt77? Or do you have an r380 gearbox already?

No brained, defender engine as you've heard it run. Take it from my experience that other peoples promises sometimes aren't worth jack.

Drove this 90 today. Engines sweet but the gearbox wants to go from 2nd to 5th and the same coming down the box.
I do have the original gearbox that was mated to the 2.5 and also the discovery box.
The gearbox makes no noises but doesn't seen to like 3/4th?

'Probably' just the bias spring, which is easy and cheap to replace. No guarantees until you have a look though.