M50TU Differences

What if any are the differneces between M50TU motors
I need a head for my 95- 525i and I have located a complete
1993- 325i (vin last 7 dig = EF40991) motor for a price I can not let pass.

will this engines head fit my engine, this way I can have it completely refurbished and when it is ready the swap would be a days work if all goes well.
or
Will the complete engine be swapable with mine, I could do a complete overhaul, spice it up a bit and when ready swap it with mine, weekend job
if all goes well.

Any opinions would be greatly appriciated

Thanks
Xavier