HELP ! , Defender 90 rear prop length ?

[Hybrid88]

Hi Can you please answer a question that is the last bit of the puzzle ( hopfully ! ) I have just finished stripping the chevy truck ready to start the build of my new project. I am using the 4L80e auto box and have been looking at using a lt230 transfer box but the cost of the conversion plate and they can't promise that it will fit as the 4l80e has a very long out put shaft to take the chevy transfer box. So thinking it maybe easyer to keep the Borgwarner 4401 transfer box from the truck. My problem is that I wanted to put it all into a Defender 90,the rover V8 + R380 + lt230 is 1400mm long but the chevy + 4l80e + Borgwarner 4401 transfer box is 1700mm long . So the question is how long is a 90 rear prop and what the shortest you could go to ? many thanks Simon