Engine & gearbox replacement

Hi all
I'm looking into changing the engine and gearbox for my series IIa landrover but are not sure what to fit. I currently have a 2.25 petrol engine, what have you all fitted or what would you all recommend?

I would like to be able to drop a complete unit straight in but would maybe be able to do some mods.

What places can anyone recommend to buy from??

What do you want to do with it? High miles & motorways? Green laning & the shops? Towing stuff? Burning Corsa's off the lights?

You can fit anything in with a bit of fettling, but it depends what you want from it.

Thanks for your reply
I want to use it for my everyday vehicle, nice and reliable (-ish!!!), reasonable fuel consumption (-ish!!!) and I wouldn't mind being able to go at 50mph as at the moment I am not getting past 43mph. I don't want to go madly fast or do any extreme off roading (although Mr voodoo might have other ideas) as I am scared of breaking it.

for economy and speed i put a perkins prima td in mine but its quite an expensive conversion but well worth it it will pay for its self in 1 months with the savings in fuel

i have a ii1 with a 2.8 daihatsu n/a in it. Its a very nice fit and the NFU accepted it with no mods 2 the brakes, i thonk if it had been a TD they would have asked for brake upgrade as well. It goes through a siii gearbox.

The other motor many would recomend is the izuzu, my local landrover bloke loves them.

I did not do my conversion so cant help with details but mine was converted from a petrol, kits are available and i am very happy with mine. Frankly the gearbox is the weak link if anything.

It has to be a V8 mate,I have a 3.6 J E engineering prepped Rover v8 with a Elderbrook carb, high comp pistons, unknown cam(prob std) mated to a standard series gearbox via an adptor ring which you can get off ebay for 60quid or so.
It's recked 3 gearboxs and 4 drive shafts(rears - turns them into a drill bit looking shaft)
I used it daily to commute from Windsor to Teddington down the M4 everyday for nealy a year and not to bad on fuel - I managed to pass 3 garages B4 more fuel was needed!! (about 17mpg on a run 12-14mpg ave and well into single figures when having fun).
How about a GMC 6.5 V8 turbo diesel 20mpg and 500lb ft torque!!!!!!!!! - these have been fitted to allsorts of LR's
I've seen a Jag V12,American v8's and V6's fitted and just about any striaght 4 cyl Perol or diesel will fit with a bit of imagination.
In south africa they fitted BWM straight sixes and Rover ohc sixes as standard.
Good luck with finding your choice of engine.

Check before you think about putting a modern engine in with altered drive chain etc as it may alter your tax exemption.
The series 2 gb is stronger that a series 3 but it does not have synchromesh on 1st or 2nd.
It maybe a better solution to fix or replace the engine you have and fit a over drive and a series 3 gearbox because the 2.25 lump is cheep, easy to work on and there is always loads around.
But if you really want a bigger engine I would follow Marcus and get a v8