The flywheel only aligns with the slanted teeth facing the trans. even the old f/wheel was mounts the same way. The starter will bolt up with out the shims, but the bendix will hits the f/wheel when I try to start the motor. To get the bendix to mess correctly I have to add about 3/8in" of shims. I’m going to try the old f/wheel in the morning to see if it is the same circumference as the new one. Does anyone have a good part number for a flywheel for a 69 Pontiac 400-auto trans.? And if so where is it located? I can’t find it on either flywheel.