[TitaniumTT]

Thanks for the heads up. My FC doesn't hop, just lights them up pretty well. She's an auto-x, track day, street car so I REALLY want to keep the Torsen rear end. We'll see how long she lasts. I'm with you, I really don't want to replace a part more than once.

Yes and sort of. I say sort of becuase I never drove with that rear end prior to the swap. I bought the whole thing used from a guy who used to race e-prod and was moving to the M3's. I got everything and promptly cracked it open for the Torsen. We moved tires around and it did nothing, swapped the driveshaft, it did nothing, it wasn't until we put my buddies Torsen in that the vibe went away. Interestingly enough the flange lines up with the bolt patern, but the ID of the flange is EVER SO slightly off. You have to beat and pry the DS off the vibrating one, but not the good one. So I need to locate a pinion flange I guess and see what that does. I didn't on this one, and I should have, press the pinion flange out and check all the tolerances. I figured if it came off a race car, it shouldn't be a problem. Not high on my priorities list right now based on where his PJ is.... hell, I even has his fuel tank in my car