E30 Zone

ive done a 2.5 conversion on my car and i need to order a new centre bearing and uj for my prop shaft but dont have a registration or chassis number to order the parts... could anyone help me out?

Rear half of E30 prop(bit that carries the centre bearing)is common to all versions,it's the front bit that changes length and fitting to suit.

GSF or ECP will be able to supply a suitable part,bearing and the rubber-lined carrier are two seperate bits,and you will only be able to get the dust cover thingy from the main stealer.

There's only two versions of the prop centre bearing, and that's pre and post facelift. The difference is in the spacing of the bolt holes.

The engine is an 86 and the chassis is an 89 so I'm guessing ill need the prefacelift version? Got one for sale?

Bearing mounts on the chassis, so it's a post facelift you need.
Not really a part I'd advise buying second hand.
P.S: I've just noticed that you mention a u/j in your OP. These aren't replaceable, so if one has failed you'll need a whole fresh prop - not just the half that's failed, as the prop is balanced as a complete item.