1989 Defender 2.5TD to Disco 300TDI Conversion help

Hi, I am looking into swapping my Defender 2.5TD engine for a 300tdi from a 1998 Discovery (Full donor car)
My Defender has a LT77 Gearbox, and the Discovery has a R380 gearbox.
Is it possible to fit the Discovery 300TDI and R380 gearbox into the defender, or must I keep using the original LT77 gearbox?
Also, is there a write up available for the 2.5 to 300 conversion? I could not find anything on a search.
Many Thanks,
Louis

You can fit a 300tdi to an LT77, using the Steve Parker conversion kit.

Have a look here for info:
https://www.steveparkers.com/conversions/

On a personal note. Also consider an RV8 conversion. The V8 is so much nicer, smoother, more refined, sounds fantastic, more power and faster. They are more thirsty, but depending on how many miles you are doing, it might not cost significantly more to run one.

300bhp/ton said:

Have a look here for info:
https://www.steveparkers.com/conversions/

On a personal note. Also consider an RV8 conversion. The V8 is so much nicer, smoother, more refined, sounds fantastic, more power and faster. They are more thirsty, but depending on how many miles you are doing, it might not cost significantly more to run one.

Click to expand...

I have personal dreams about fitting a V8. I keep looking at 3.5 V8 efi's on Ebay. But my wife would actually kill me, and then to spite me she'd scrap my Ninety.

Pappasmurf said:

You can fit a 300tdi to an LT77, using the Steve Parker conversion kit.

Click to expand...

Or by drilling and tapping the backplate of the tdi to add the extra stud and by taking a stud out

Pappasmurf said:

I have personal dreams about fitting a V8. I keep looking at 3.5 V8 efi's on Ebay. But my wife would actually kill me, and then to spite me she'd scrap my Ninety.

Click to expand...

Yeah I hankering after a v8, think I would want 4l + though and fuel injection and a straight through exhaust

Pappasmurf said:

I have personal dreams about fitting a V8. I keep looking at 3.5 V8 efi's on Ebay. But my wife would actually kill me, and then to spite me she'd scrap my Ninety.

Click to expand...

lol

I'd probably look for a cheap or breaking p38 or D2 with a 4.0 or 4.6

flat said:

Yeah I hankering after a v8, think I would want 4l + though and fuel injection and a straight through exhaust

Click to expand...

See I want more of a street sleeper. You don't know it's a beast until you put your foot down. Besides the wife would hate the noise.

If your R380 gear-box is a good one, you can fit the engine and gear-box from the Discovery, you will have to cut the engine mounts off the Discovery chassis and weld them in exactly the same place on your Defender chassis.
You will need to use the Discovery gear-box cross member and front prop, you will also need a longer 300tdi rear prop.
The R380 transmission tunnel is also different and the Discovery gear lever is in the wrong place, it comes up through the front of the seat box unless you modify it.
The advantage of using the R380 is that it is a better box and with your engine in the standard 300tdi position you can use standard 300tdi radiator hoses, oil pipes, PAS pipes exhaust etc.

If your LT77 is the better box, the 300tdi will bolt onto the LT77 bellhousing minus a couple of studs and with an extra stud fitted at the bottom. The engine ends up in the same position as your 2.5TD engine, you don't have to mess with the props and gear lever, but you will have to extend hoses between the engine and radiator, intercooler etc and modify the front section of the exhaust.
People also say that you can't use the standard 300tdi viscous fan with the LT77 as it is too far back, but I have and have experienced no problems.

If you go for the LT77, use the Steve Parker weld on engine mounts, it will save a lot of bugg3ring about.