Seeing as you'll have the engine apart this is a very good upgrade https://www.ebay.co.uk/itm/BMW-E46-318d-32...SwuMFUmTCE

and one of these if it hasn't already been fitted (check first as most have been done!) https://www.ebay.co.uk/itm/FOR-BMW-DIESEL-...SwIX1Z4HYc Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

Thank for that , I'll be going up there regularly to check on the progress as I know Steve well , big non urgent jobs tend to go on the back burner if I'm not there giving him a prod ! I've ordered the egr kit and will check the other as you suggest

This new engine has done 30k less than the old one, it has the fuel pump and injectors in it but not the turbo , Steve is planning on changing the inlet manifold as suggested but also pump and injectors from the old engine

Is that a plan with the most chance of success or are they likely to be the same

I wouldn't bother personally, but I would have the pump, injectors, starter, alternator off the old lump as spares! Why change unnecessary parts, I'd stick with the parts it came with and save as much of the old engine as possible.. You know that everything is good on the engine your car came with except 1 cylinder  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

Thanks, had a chat and we're going with the new engine as is, I'll end up with loads of spare parts, AC pump, wiring looms, alternator , sensors , not sure I'll go as far as pistons and internals but all the bits on the outside will be going in a box, not that I'm likely to need them as it's going to be mega reliable