I've run my gm maft with the connector facing up down and to the one side since i do'nt have enough clearance to run it on the other side. Currently i have it with the connector facing up and out at an angle. I have never had any problems in any config and i was getting the same gram/rev with...
The rotation on a Gm sensor will not make a difference because of the style of sensor it is. A mustang sensor is a sample tube sensor and only get a fraction of the air sensored that goes into the tube and if it's not rotated correctly not enough air will get into the tube making the reading...