I not being a smart ass but I did the swap in 2 weekends going from a rb20 with a broken timing belt to a running rb25 using a series 2 rb25, wiring harness and ecu.
I used all the r32 alternator, starter, power steering pump, a/c compressor, engine mounts and harmonic balancer. So it bolted back in as if it was always there then modified the r33 harness using the 32 body plugs (in the cabin) and fired it up and never had an issue, it was my daily driver and everything worked as per factory