You found that nut right?
If not, don't bother looking to hard, just get to work taking the head off.
You didn't do any cam work did you?
Sometimes the hydraulic lifters will make a little noise if you haven't fired it up for a while. Hopefully that's it.
Glad everything went O.K. BTW how much did Eurospeed charge for the kit?
1997 Z3 with N/A power adders....