My thoughts are that the E34 was probably designed for the M50 but with the V8 in mind. (In Europe I also saw 4 cyl E34's) I think the weight and balance of the V8 probably wouldnt upset the 6 too much. If springs from an E34 540 would fit, that would be the way to go. As far as the other front end components, well, the S38 engine wasn't a lightweight either... Try contacting Schneller Motorsports in Amesbury MA. These guys are transplant specialists. They even stuffed an E34 M5 motor into an E30! Good luck, let us know if you go through with it!