Automatic\manual Engine replacement help needed.

I need some help with a conversion.
My daughters 1991 Geo Prizm 1.6 motor died. It is an Automatic Trans. I replaced it with a motor from a 1991 Corolla that was a Manual transmission. there is a 1'5 inch gap between the new flex plate and the Torque coverter. If I screw in and draw in the Coverter in tight it "Unlocks" from the transmission. Apparently the Crank on the automatic is longer than the Manual engine. Has anyone run into this? Does someone make a Spacer tha can be added rather than replacing the Crank ? I am about ready to sell this perfect running motor and sell the car..Any suggestions would be appreciated.. Thanks