Trouble mating 727 to a 440 - HELP ;)

Hey everyone, frustrating afternoon. Finally got enough free time to try and mate the 727 to the 440, and it didn't fit. The Bell Housing stands off about 1/2 - 3/4" from the engine. The Bolt holes line up perfectly, and the Converter is inserted all the way into the Trans input shaft, but when I tighten them can't pull the transmission in any closer than 1/2" Obviously these didn't come out of the same car, and think this may be have mated to the 400 before.

Any suggestions, are there spacer plates available?

Thanks

Pat