| smokey, i had a smoking 310 sprinter also, i popped the head off to do the glow plugs, as it was easier, and did the head gasket obviously at same time.
but the smoking seemed to be from the marks in the bores.
i got reduced fuel milage etc.. and burned quite a bit of oil.
i dropped 3/4 litre of ametech restore in the engine, and after a bit of driving, all was well again, lots more power, no oil consumption worth mentioning, and the engine sounds sweet as a nut now.
definately worth a try , honestly!
bad point is that its 50 quid a litre.
but its cheaper than ripping the engine to bits. | 
