[Project] M57 swap into E87 – looking for advice

Planning an M57 swap into my E87 and looking for advice from anyone who’s done it.

The plan is a 160 kW M57 with stock E60 535d twins, aiming for around 250–260 kW. I’ve already got a complete 123d donor car for parts.

For those who’ve done an M57 swap into an E8x chassis (E81/E82/E87/E88), what did you actually need to make it work? Engine mounts, gearbox/clutch, propshaft, cooling, wiring, coding, exhaust, diff, etc.

What were the biggest headaches during the swap? Anything you wish you’d known before starting?

Any build threads, parts lists, photos, or advice would be massively appreciated.