Hi, I need some info and advice Ive got a series 2a swb petrol and looking to put bmw 2.5 turbo diesel 6 cylinder in to it will it fit and if it does will i need modify the fly wheel and clutch? is there a modifying kit to do this?

Just make it up as you go along as long as you have a welder and grinder

why bother,get a jap lump if ya gunna bodge it,they work better.

guy on here called tig has put a 300bhp straight six in his series. He'll prob be along here later to give you some more info

I did indeed! M5 straight six to be precise. not quite a series, registered as one but far from it really!
Personally I found it quite easy to make the adapter plate but it does depend on your skills. I used a range rover/disco v8 box (lt77 or r380 will both work). this was because it was the easiest way to make the plate as the bellhousing is a wider diameter then the engine.
with some careful measuring i'm sure you could make the diesel fit a series box although i dont think it would handle the torque. The easiest thing to do would be get the engine and manual box from a p38 rangey and try and keep the engine far forward to help with your gearstick placement and to keep a good length of rear prop.
Then you have the issue of perm 4x4 with front ujs in the swivels, not the best.
where do you end!
I am currently preparing mine for next years wyedean rally and am rebuilding basically the whole thing as we speak. will probably change a load of things whilst i'm doing it.
unfortunately once you start modifying to this degree you will never stop as something could always be made slightly better.

thanx for the advice by the sounds of it I will probably put a v8 box in i didnt think the series box would take the power of the diesel