Flex plate

I am restoring a 73 duster 340 all numbers sunroof car. It is an automatic. When I bought the car it was completely apart. Now the 340 is rebuilt and I am mating the trans to the motor. I have the torque convertor slid in place and have the flex plate mounted to the motor. My problem is I can only get 3 of the 4 holes to line up on the flex plate to convertor. The 4 hole is about a 1/2 of a hole off. I have tried all 4 holes but none will all line up. . . . help. Any ideas?