4.6 Rover and 4HP22 installation

[soc135even]

Hi,
New to the SOC. Saved a Stag a few years ago but it had an old v6 that was dead and a TH400 transmission.
I have been collecting parts and found a 4.6 discovery engine. A 4HP22 from a Disco I (1998) and a 4HP22 from a late 80's BMW 325.
Trying to understand what parts i will need to make all this work.
I believe i use the internals and tail housing from the BMW in the housing from the Discovery.
Not sure what torque convertor i need to use? can i use the one from the Disco I transmission? will it work with the Disco II flex plate?
Thanks in advance for any advice.
Regards
Joe

[Phil S]

I would think you would need to dry fit the box to the engine and see what lines up with either box/torque converter/drive plate, going to these lengths you may as well opt for an electronic hall effect speedo

[bullstarz]

You can get pretty much anything to fit it’s just a case of persevering and seeing if anybody else has fitted that engine to that gearbox. Plus not been done on the stag but no doubt somebody somewhere is done the same to a different car. There’s been lots of cars fitted both factory and retrofitted with a Rover V8 it is many different forms. It’s a good engine, those higher capacity Rover V8 I think are stokers engines and don’t like to rev but have lots of low down torque. So one thing to make sure that that gearbox can actually handle that amount of torque and the gear ratios match the engine. Might also be a good idea to swap the diff and halfshafts as you probably destroy the original triumph ones quite quickly. As you’ve got the fuel injected engine the plenum chamber is too high to fit under the bonnet, so you will have to put spaces on the front crossmember so you can drop the engine down lower. Also you will have to have the base of the plenum machine unless you want to have a bonnet bulge on the car. It’s a personal choice a majority people like a Smoove bonnet, but there has been a few that do look really good having a professionally installed/made bonnet bulge.