Mike my opinion by looking at the factory manual for 47 to 54 truck manual it would go like this . You would need two rubber support cushions, one would be placed between the frame and the radiator support and the other one would be placed underneath the frame. Also the extra flat plate could actualy be a shim that would sit on top of the cross member. So if you were to look at it it would look like this: top to bottom
1. radiator support
2. support cushion
3. support cushion plate
4. cross member
5. support cushion
6. support cushion lock plate

Then the carrige bolt would drop down and you would install the hex nut. Maybe you could also add a lock washer to take up a little more of length of the bolt. Good luck Joe B.