I have a 1988 BMW 535i. I have previously owned a 1987 535is. The two motors looked a little different (mainly the way the cruise control unit looked). My friend has a 1988 735i and his motor looks exactly like the one in my 535i, but different from the motor in my 1987 535is. Is there a chance that I have the higher HP motor in my 1988 535i? It sure feels like it.