how much would a zoner charge

[Dave_M3]

If ALL the parts (and I mean everything from the little E34 steering joints to the donor car itself to take the engine from) are supplied, about 1500-2K for doing it and thats with it being a job that you do over a month or so when you get a few hours spare here and there.

There's easily 100-150 hours in doing the conversion properly.