I found more out about the swap we are performing. The engine came out of an early year 1997 OB wagon going into a 1999 OB wagon. We have done 3 engine swaps in other OB's after swapping the motors checking all connections, cam & crank sensors and timing the motor backfires and will not start. We have not hooked up the exhaust, does that matter? Can anyone think of any other possible problems? Any help is appreciated.