My previous car was 83 533i 3spd automatic. Had autothority chip, MM exhaust, ported exhaust manifolds, Bilsteins, suspension techniques springs/sway bars, E34 wheels/tires, adjustable fuel pressure regulator, MSD ignition, K&N hi-perf filter. Got a good deal on 89 M30 engine and swapped engines and kept the 533 injectors, adjustable regulator and orignial ECU. Loved the car but a 91 535ia came along and after a test drive decided it was so more refined and the price was right. Performance feels about the same with engine and tran chip. E34 is much smoother, quieter and feels more luxurious. Gas mileage is much worse as car is heavier. Wife wouldn't let me keep my play car.