the E34 m5 subframe can withstand it with the factory m5 diff, all the mounts have to be urethane though I know because there is is an M5 down here with 1000whp and beats on the car like a red headed step child. Plus I owned an e36 and blew the rear end off of it, after that i did researsh and found out that its one of the e36 weakpoints, the mounts for the diff on the e36 can't stand the pressure mostly because its designed for smoothness not a huge amount of power.