Good point !!! but no this is a totally different engine combo . I think I might have found the problem : when I took the motor out the passenger side motor mount rubber was broken , when I last changed the oil during winter maintenance I found loose bell housing bolts on the same side . Although I have a torque strap on the drivers side I am thinking the broken motor mount is causing the engine to move around thus causing the bolts to come loose and cracking the flex plate . I am thinking I need solid motor mounts . BTW its an ATI Super Damper rebuilt by them 2 years ago and the motor was on the dyno ( thats how I know the hp. and tq. numbers ) before installation in the car