E30 Zone

Hi guys,
I have bmw e30 316 (m10 with carb) and i was planning to buy old 1993 bmw e34 525i (m50b25, not m20b25). Which parts i can take out of donor car, and can i keep my diff (3.91)?
I am looking for the cheapest option because i will need to upgrade my brakes and suspension too.
sorry for bad english

Sump and pickup tube should be ok.
Engine mounts/gear box mounts will be needed (from 535 x2 for engine mounts and e21 for gear box x2). E36 engine arms will be needed. Just keep everything e34/e30 related (engine bits, wiring, gear box stuff, diff, drive train, radiator, houses, ECU, wiring loom, mounting brackets) you can always throw away whats not necessary. or maybe sell them as you getting hole donor car. Also clio brake servo unless you going some more complicated way.