A couple of people at the Buick Factory 36 (built the 3800 motors) reunion have over 400,000 miles on their original motors and trannies. The 3800's were built "to spec" and the lobby to Factory 36 had a wall full of awards for quality. I've got 280k on my '98 and 178k on my GTP. I'm expecting the bodies will fail before the powertrain does on both cars.