FE has a 184t flexplate, Windsor has a 164t flexplate. Googling established 2 x different size pilot bushing, 1.375" and 1.848" size. C6s from different engine families are not interchangeable due to bellhousing bolt pattern differences, one piece case with non detachable bellhousings. Couldn't locate anything on differences from FE to Windsor but feel that full size FEs could be different and larger than smaller compact Windsors?
No, the torque convertor won't work. I believe that the standoff heights on the torque convertor are different. I can't remember exactly, but the convertor will either smash into the pump or not engage it properly. Also, why would you want to put a torque convertor that is set up for a low revving torque motor (390) behind a high revving small block??? Talk about setting your self up for poor performance.